This project is mirrored from https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git.
Pull mirroring updated .
- 08 Sep, 2021 2 commits
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Takashi Iwai authored
commit 4267c5a8 upstream. The recent change for low latency playback works in most of test cases but it turned out still to hit errors on some use cases, most notably with JACK with small buffer sizes. This is because USB-audio driver fills up and submits full URBs at the beginning, while the URBs would return immediately and try to fill more -- that can easily trigger XRUN. It was more or less expected, but in the small buffer size, the problem became pretty obvious. Fixing this behavior properly would require the change of the fundamental driver design, so it's no trivial task, unfortunately. Instead, here we work around the problem just by switching back to the old method when the given configuration is too fragile with the low latency stream handling. As a threshold, we calculate the total buffer bytes in all plus one URBs, and check whether it's beyond the PCM buffer bytes. The one extra URB is needed because XRUN happens at the next submission after the first round. Fixes: 307cc9ba ("ALSA: usb-audio: Reduce latency at playback start, take#2") Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210827203311.5987-1-tiwai@suse.de Signed-off-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Takashi Iwai authored
commit 7af5a143 upstream. We've got a regression report for USB-audio with Sony WALKMAN NW-A45 DAC device where no sound is audible on recent kernel. The bisection resulted in the code change wrt endpoint management, and the further debug session revealed that it was caused by the order of the USB audio interface. In the earlier code, we always set up the USB interface at first before other setups, but it was changed to be done at the last for UAC2/3, which is more standard way, while keeping the old way for UAC1. OTOH, this device seems requiring the setup of the interface at first just like UAC1. This patch works around the regression by applying the interface setup specifically for the WALKMAN at the beginning of the endpoint setup procedure. This change is written straightforwardly to be easily backported in old kernels. A further cleanup to move the workaround into a generic quirk section will follow in a later patch. Fixes: bf6313a0 ("ALSA: usb-audio: Refactor endpoint management") Cc: <stable@vger.kernel.org> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=214105 Link: https://lore.kernel.org/r/20210824054700.8236-1-tiwai@suse.de Signed-off-by:
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- 05 Jul, 2021 1 commit
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gushengxian authored
Fix some spelling mistakes as follows: altenate ==> alternate compatbile ==> compatible perfoms ==> performs dont'register ==> don't register periodicaly ==> periodically arount ==> around Signed-off-by:
gushengxian <gushengxian@yulong.com> Link: https://lore.kernel.org/r/20210705120052.665212-1-gushengxian507419@gmail.com Signed-off-by:
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- 02 Jun, 2021 1 commit
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Takashi Iwai authored
The PCM delay accounting in USB-audio driver is a bit complex to follow, and this is an attempt to improve the readability and provide some potential fix. Basically, the PCM position delay is calculated from two factors: the in-flight data on URBs and the USB frame counter. For the playback stream, we advance the hwptr already at submitting URBs. Those "in-flight" data amount is now tracked, and this is used as the base value for the PCM delay correction. The in-flight data is decreased again at URB completion in return. For the capture stream, OTOH, there is no in-flight data, hence the delay base is zero. The USB frame counter is used in addition for correcting the current position. The reference frame counter is updated at each submission and receiving time, and the difference from the current counter value is taken into account. In this patch, each in-flight data bytes is recorded in the new snd_usb_ctx.queued field, and the total in-flight amount is tracked in snd_usb_substream.inflight_bytes field, as the replacement of last_delay field. Note that updating the hwptr after URB completion doesn't work for PulseAudio who tries to scratch the buffer on the fly; USB-audio is basically a double-buffer implementation, hence the scratching the buffer can't work for the already submitted data. So we always update hwptr beforehand. It's not ideal, but the delay account should give enough correctness. Link: https://lore.kernel.org/r/20210601162457.4877-4-tiwai@suse.de Signed-off-by:
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- 26 Apr, 2021 1 commit
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Takashi Iwai authored
The recent endpoint management change for implicit feedback mode added a clearance of ep->sync_sink (formerly ep->sync_slave) pointer at snd_usb_endpoint_stop() to assure no leftover for the feedback from the already stopped capture stream. This turned out to cause a regression, however, when full-duplex streams were running and only a capture was stopped. Because of the above clearance of ep->sync_sink pointer, no more feedback is done, hence the playback will stall. This patch fixes the ep->sync_sink clearance to be done only after all endpoints are released, for addressing the regression. Reported-and-tested-by:
Lucas Endres <jaffa225man@gmail.com> Fixes: bf6313a0 ("ALSA: usb-audio: Refactor endpoint management") Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210426063349.18601-1-tiwai@suse.de Signed-off-by:
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- 14 Apr, 2021 1 commit
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Takashi Iwai authored
During the recent rewrite of the implicit feedback support, we've tested to apply the implicit fb on BOSS devices, but it failed, as the capture stream didn't start without the playback. As the end result, it got another type of quirk for tying both streams but starts playback always (commit 6234fdc1 "ALSA: usb-audio: Quirk for BOSS GT-001"). Meanwhile, Mike Oliphant has tested the real implicit feedback mode for the playback again with the latest code, and found out that it actually works if the initial feedback sync is skipped; that is, on those BOSS devices, the playback stream has to be started at first without waiting for the capture URB completions. Otherwise it gets stuck. In the rest operations after the capture stream processed, we can take them as the implicit feedback source. This patch is an attempt to improve the support for BOSS devices with the implicit feedback mode in the way described above. It adds a new flag to snd_usb_audio, playback_first, indicating that the playback stream starts without sync with the initial capture completion. This flag is set in the quirk table with the new IMPLICIT_FB_BOTH type. Reported-and-tested-by:
Mike Oliphant <oliphant@nostatic.org> Link: https://lore.kernel.org/r/20210414083255.9527-1-tiwai@suse.de Signed-off-by:
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- 08 Feb, 2021 3 commits
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Takashi Iwai authored
In the later patch, we're going to issue the PCM sync_stop calls at disconnection. But currently the USB-audio driver can't handle it because it has a check of shutdown flag for stopping the URBs. This is basically superfluous (the stopping URBs are safe at disconnection state), so let's drop the check. Fixes: dc5eafe7 ("ALSA: usb-audio: Support PCM sync_stop") Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210206203052.15606-4-tiwai@suse.de Signed-off-by:
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Takashi Iwai authored
The endpoint management has bit flags to indicate the current state, and we're dealing two things: the running bit and the stopping bit. There is a thin window in transition from the running to the stopping in stop_urbs(), and as long as the bit flags are used, it's difficult to plug. This patch modifies the state management code to use the atomic int and follow the explicit three states, STOPPED, RUNNING and STOPPING. The state change is done via atomic_cmpxhg() for avoiding possible races, and check the state change more strictly. The unexpected state change is now handled as an error. Fixes: d0f09d1e ("ALSA: usb-audio: Refactoring endpoint URB deactivation") Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210206203052.15606-3-tiwai@suse.de Signed-off-by:
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Takashi Iwai authored
When we stop an endpoint in release_urbs(), it ignores the inconsistent endpoint state and tries to release the resources. This shouldn't happen in theory, but it's still safer to abort the release and let the caller proper error handling. Also, stop_and_unlink_urbs() called from release_urbs() does two step works, and it's more straightforward to split this to two functions again, so that the call from the PCM trigger won't take the path with sleeping. This patch modifies the EP management code to adapt two points above. Fixes: d0f09d1e ("ALSA: usb-audio: Refactoring endpoint URB deactivation") Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210206203052.15606-2-tiwai@suse.de Signed-off-by:
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- 05 Feb, 2021 1 commit
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Takashi Iwai authored
The kerndoc comment for the new function snd_usb_endpoint_free_all() had a typo wrt the argument name. Fix it. Fixes: 00272c61 ("ALSA: usb-audio: Avoid unnecessary interface re-setup") Reported-by:
Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210205082837.6327-1-tiwai@suse.de Signed-off-by:
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- 18 Jan, 2021 1 commit
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Takashi Iwai authored
The UAC2/3 sample rate setup is based on the clock node, which is usually shared in the interface, and can't be re-setup without deselecting the interface once, and that's how the current code behaves. OTOH, the sample rate setup of UAC1 is per endpoint, hence we basically need to call for each endpoint usage even if those share the same interface. This patch fixes the behavior of UAC1 to call always snd_usb_init_sample_rate() in snd_usb_endpoint_configure(). Fixes: bf6313a0 ("ALSA: usb-audio: Refactor endpoint management") Link: https://lore.kernel.org/r/20210118075816.25068-3-tiwai@suse.de Signed-off-by:
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- 08 Jan, 2021 2 commits
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Takashi Iwai authored
There are devices that have multiple endpoints sharing the same iface/altset not only for sync but also for the actual streams, and the audioformat for such an endpoint needs to be handled with the proper endpoint index; otherwise it confuses the endpoint management. This patch extends the audioformat to annotate the endpoint index, and put the proper ep_idx=1 to Pioneer device quirk entries accordingly. Fixes: bf6313a0 ("ALSA: usb-audio: Refactor endpoint management") Link: https://lore.kernel.org/r/20210108075219.21463-5-tiwai@suse.de Signed-off-by:
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Takashi Iwai authored
The current endpoint handling assumed (more or less) a unique 1:1 relation between the endpoint and the iface/altset. The exception was the sync EP without the implicit feedback which has usually the secondary EP of the same altset. This works fine for most devices, but it turned out that some unusual devices like Pinoeer's ones have both playback and capture endpoints in the same iface/altsetting and use both for the implicit feedback mode. For handling such a case, we need to extend the endpoint management to take the shared interface into account. This patch does that: it adds a new object snd_usb_iface_ref for managing the reference counts of the each USB interface that is used by each endpoint. The interface setup is performed only once for the (sharing) endpoints, and the doubly initialization is avoided. Along with this, the resource release of endpoints and interface refcounts are put into a single function, snd_usb_endpoint_free_all() instead of looping in the caller side. Fixes: bf6313a0 ("ALSA: usb-audio: Refactor endpoint management") Link: https://lore.kernel.org/r/20210108075219.21463-4-tiwai@suse.de Signed-off-by:
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- 23 Nov, 2020 14 commits
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Takashi Iwai authored
Just for consistency, use unsigned char for iface and altsetting in allover places. Also rearrange the field positions of snd_usb_endpiont and tidy up with some comments. Tested-by:
Keith Milner <kamilner@superlative.org> Tested-by:
Dylan Robinson <dylan_robinson@motu.com> Link: https://lore.kernel.org/r/20201123085347.19667-35-tiwai@suse.de Signed-off-by:
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Takashi Iwai authored
Follow the inclusive terminology, just replace sync_master/sync_slave with sync_source/sync_sink. It's also a bit clearer from its meaning, too. Tested-by:
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Takashi Iwai authored
There are two places calculating the next packet size for the playback stream in the exactly same way. Provide the single helper for this purpose and use it from both places gracefully. Tested-by:
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Takashi Iwai authored
Minor code refactoring to consolidate the URB deactivation code in endpoint.c. A slight behavior change is that the error handling in snd_usb_endpoint_start() leaves EP_FLAG_STOPPING now. This should be synced with the later PCM sync_stop callback. Tested-by:
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Takashi Iwai authored
The endpoint objects may be started/stopped concurrently by different substreams in the case of implicit feedback mode, while the current code handles the reference counter without any protection. This patch changes the refcount to atomic_t for avoiding the inconsistency. We need no reference_t here as the refcount goes only up to 2. Also the name "use_count" is renamed to "running" since this is about actually the running status, not the open refcount. Tested-by:
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Takashi Iwai authored
The audioformat is referred in many places but most of usages are read-only. Let's add const prefix in the possible places. Tested-by:
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Takashi Iwai authored
The implicit feedback mode uses a ring buffer for storing the received packet sizes from the feedback source, and the code has a slight flaw; when a playback stream stalls by some reason and the URBs aren't processed, the next_packet FIFO might become empty, but the driver can't distinguish whether it's empty or full because it's managed with read_poss and write_pos. This patch addresses those by changing the next_packet array management. Instead of keeping read and write positions, now the head position and the queued amount are kept. It's easier to understand about the emptiness. Also, the URB active flag is now cleared before calling queue_pending_output_urbs() for avoiding (theoretically) possible inconsistency. Tested-by:
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Takashi Iwai authored
This is an intensive surgery for the endpoint and stream management for achieving more robust and clean code. The goals of this patch are: - More clear endpoint resource changes - The interface altsetting control in a single place Below are brief description of the whole changes. First off, most of the endpoint operations are moved into endpoint.c, so that the snd_usb_endpoint object is only referred in other places. The endpoint object is acquired and released via the new functions snd_usb_endpoint_open() and snd_usb_endpoint_close() that are called at PCM hw_params and hw_free callbacks, respectively. Those are ref-counted and EPs can manage the multiple opens. The open callback receives the audioformat and hw_params arguments, and those are used for initializing the EP parameters; especially the endpoint, interface and altset numbers are read from there, as well as the PCM parameters like the format, rate and channels. Those are stored in snd_usb_endpoint object. If it's the secondary open, the function checks whether the given parameters are compatible with the already opened EP setup, too. The coupling with a sync EP (including an implicit feedback sync) is done by the sole snd_usb_endpoint_set_sync() call. The configuration of each endpoint is done in a single shot via snd_usb_endpoint_configure() call. This is the place where most of PCM configurations are done. A few flags and special handling in the snd_usb_substream are dropped along with this change. A significant difference wrt the configuration from the previous code is the order of USB host interface setups. Now the interface is always disabled at beginning and (re-)enabled at the last step of snd_usb_endpoint_configure(), in order to be compliant with the standard UAC2/3. For UAC1, the interface is set before the parameter setups since there seem devices that require it (e.g. Yamaha THR10), just like how it was done in the previous driver code. The start/stop are almost same as before, also single-shots. The URB callbacks need to be set via snd_usb_endpoint_set_callback() like the previous code at the trigger phase, too. Finally, the flag for the re-setup is set at the device suspend through the full EP list, instead of PCM trigger. This catches the overlooked cases where the PCM hasn't been running yet but the device needs the full setup after resume. Tested-by:
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Takashi Iwai authored
The prepare_data_urb and retire_data_urb fields of the endpoint object are set dynamically at PCM trigger start/stop. Those are evaluated in the endpoint handler, but there can be a race, especially if two different PCM substreams are handling the same endpoint for the implicit feedback case. Also, the data_subs field of the endpoint is set and accessed dynamically, too, which has the same risk. As a slight improvement for the concurrency, this patch introduces the function to set the callbacks and the data in a shot with the memory barrier. In the reader side, it's also fetched with the memory barrier. There is still a room of race if prepare and retire callbacks are set during executing the URB completion. But such an inconsistency may happen only for the implicit fb source, i.e. it's only about the capture stream. And luckily, the capture stream never sets the prepare callback, hence the problem doesn't happen practically. Tested-by:
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Takashi Iwai authored
start_endpoints() may leave the data endpoint running if an error happens at starting the sync endpoint. We should stop both streams properly, instead. While we're at it, move the debug prints into the endpoint.c that is a more suitable place. Tested-by:
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Takashi Iwai authored
Currently snd_usb_endpoint objects are created at first when the substream is opened and tries to assign the endpoints corresponding to the matching audioformat. But since basically the all endpoints have been already parsed and the information have been obtained, we may create the endpoint objects statically at the init phase. It's easier to manage for the implicit fb case, for example. This patch changes the endpoint object management and lets the parser to create the all endpoint objects. This change shouldn't bring any functional changes. Tested-by:
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Takashi Iwai authored
In the current code, there is no check at the stream open time whether the endpoint is being already used by others. In the normal operations, this shouldn't happen, but in the case of the implicit feedback mode, it's a common problem with the full duplex operation, because the capture stream is always opened by the playback stream as an implicit sync source. Although we recently introduced the check of such a conflict of parameters at the PCM hw_params time, it doesn't give any hint at the hw_params itself and just gives the error. This isn't quite comfortable, and it caused problems on many applications. This patch attempts to make the parameter handling easier by introducing the strict hw constraint matching with the counterpart stream that is being used. That said, when an implicit feedback playback stream is running before a capture stream is opened, the capture stream carries the PCM hw-constraint to allow only the same sample rate, format, periods and period frames as the running playback stream. If not opened or there is no conflict of endpoints, the behavior remains as same as before. Note that this kind of "weak link" should work for most cases, but this is no concrete solution; e.g. if an application changes the hw params multiple times while another stream is opened, this would lead to inconsistencies. Tested-by:
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Takashi Iwai authored
There are a few rooms for improvements wrt the debug prints: - The EP debug print is shown only at starting, not at stopping - The EP debug print contains useless object addresses - Some helpers show the urb and the EP object addresses, too This patch addresses those shortcomings. Tested-by:
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Takashi Iwai authored
Factor out the code to obtain snd_usb_endpoint object matching with the given endpoint. It'll be used in the later patch to add the implicit feedback hw-constraint. No functional change by this patch itself. Tested-by:
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- 06 Oct, 2020 1 commit
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Randy Dunlap authored
Drop the duplicated word "there". Signed-off-by:
Randy Dunlap <rdunlap@infradead.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: alsa-devel@alsa-project.org Link: https://lore.kernel.org/r/20201005191244.23902-1-rdunlap@infradead.org Signed-off-by:
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- 27 Jul, 2020 1 commit
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Xu Wang authored
usb_free_coherent() is safe with NULL addr and this check is not required. Signed-off-by:
Xu Wang <vulab@iscas.ac.cn> Link: https://lore.kernel.org/r/20200727025208.8739-1-vulab@iscas.ac.cn Signed-off-by:
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- 16 Jul, 2020 1 commit
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Kees Cook authored
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by:
Kees Cook <keescook@chromium.org>
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- 30 Jun, 2020 2 commits
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Alexander Tsoy authored
Replace several occurences of "frame" with a "packet" where appropriate. Signed-off-by:
Alexander Tsoy <alexander@tsoy.me> Link: https://lore.kernel.org/r/20200629025934.154288-2-alexander@tsoy.me Signed-off-by:
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Alexander Tsoy authored
Commit f0bd62b6 ("ALSA: usb-audio: Improve frames size computation") introduced a regression for devices which have playback endpoints with bInterval > 1. Fix this by taking ep->datainterval into account. Note that frame and fps are actually mean packet and packets per second in the code introduces by the mentioned commit. This will be fixed in a follow-up patch. Fixes: f0bd62b6 ("ALSA: usb-audio: Improve frames size computation") BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=208353 Signed-off-by:
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- 15 May, 2020 1 commit
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Erwin Burema authored
For USB sound devices using implicit feedback the endpoint used for this feedback should be able to be opened twice, once for required feedback and second time for audio data. This way these devices can be put in duplex audio mode. Since this only works if the settings of the endpoint don't change a check is included for this. This fixes bug 207023 ("MOTU M2 regression on duplex audio") and should also fix bug 103751 ("M-Audio Fast Track Ultra usb audio device will not operate full-duplex") Fixes: c2491779 ("ALSA: usb-audio: add implicit fb quirk for MOTU M Series") Signed-off-by:Erwin Burema <e.burema@gmail.com> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=207023 BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=103751 Link: https://lore.kernel.org/r/2410739.SCZni40SNb@alpha-wolf Signed-off-by:
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- 24 Apr, 2020 2 commits
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Takashi Iwai authored
The linked list entry from FIFO is peeked at queue_pending_output_urbs() but the actual element pop-out is performed outside the spinlock, and it's potentially racy. Do delete the link at the right place inside the spinlock. Fixes: 8fdff6a3 ("ALSA: snd-usb: implement new endpoint streaming model") Link: https://lore.kernel.org/r/20200424074016.14301-1-tiwai@suse.de Signed-off-by:
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Alexander Tsoy authored
For computation of the the next frame size current value of fs/fps and accumulated fractional parts of fs/fps are used, where values are stored in Q16.16 format. This is quite natural for computing frame size for asynchronous endpoints driven by explicit feedback, since in this case fs/fps is a value provided by the feedback endpoint and it's already in the Q format. If an error is accumulated over time, the device can adjust fs/fps value to prevent buffer overruns/underruns. But for synchronous endpoints the accuracy provided by these computations is not enough. Due to accumulated error the driver periodically produces frames with incorrect size (+/- 1 audio sample). This patch fixes this issue by implementing a different algorithm for frame size computation. It is based on accumulating of the remainders from division fs/fps and it doesn't accumulate errors over time. This new method is enabled for synchronous and adaptive playback endpoints. Signed-off-by:
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- 13 Nov, 2019 1 commit
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Henry Lin authored
While output urb's snd_complete_urb() is executing, calling prepare_outbound_urb() may cause endpoint stopped before prepare_outbound_urb() returns and result in next urb submitted to stopped endpoint. usb-audio driver cannot re-use it afterwards as the urb is still hold by usb stack. This change checks EP_FLAG_RUNNING flag after prepare_outbound_urb() again to let snd_complete_urb() know the endpoint already stopped and does not submit next urb. Below kind of error will be fixed: [ 213.153103] usb 1-2: timeout: still 1 active urbs on EP #1 [ 213.164121] usb 1-2: cannot submit urb 0, error -16: unknown error Signed-off-by:
Henry Lin <henryl@nvidia.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191113021420.13377-1-henryl@nvidia.com Signed-off-by:
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- 30 May, 2019 1 commit
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Thomas Gleixner authored
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Reviewed-by:
Allison Randal <allison@lohutok.net> Reviewed-by:
Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by:
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- 01 Aug, 2018 1 commit
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Colin Ian King authored
Pointer 'urb' is being assigned but is never used hence it is redundant and can be removed. Cleans up clang warning: warning: variable 'urb' set but not used [-Wunused-but-set-variable] Signed-off-by:
Colin Ian King <colin.king@canonical.com> Signed-off-by:
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- 05 Jan, 2017 2 commits
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Ioan-Adrian Ratiu authored
Testing EP_FLAG_RUNNING in snd_complete_urb() before running the completion logic allows us to save a few cpu cycles by returning early, skipping the pending urb in case the stream was stopped; the stop logic handles the urb and sets the completion callbacks to NULL. Signed-off-by:
Ioan-Adrian Ratiu <adi@adirat.com> Signed-off-by:
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Ioan-Adrian Ratiu authored
Commit 16200948 ("ALSA: usb-audio: Fix race at stopping the stream") was incomplete causing another more severe kernel panic, so it got reverted. This fixes both the original problem and its fallout kernel race/crash. The original fix is to move the endpoint member NULL clearing logic inside wait_clear_urbs() so the irq triggering the urb completion doesn't call retire_capture/playback_urb() after the NULL clearing and generate a panic. However this creates a new race between snd_usb_endpoint_start()'s call to wait_clear_urbs() and the irq urb completion handler which again calls retire_capture/playback_urb() leading to a new NULL dereference. We keep the EP deactivation code in snd_usb_endpoint_start() because removing it will break the EP reference counting (see [1] [2] for info), however we don't need the "can_sleep" mechanism anymore because a new function was introduced (snd_usb_endpoint_sync_pending_stop()) which synchronizes pending stops and gets called inside the pcm prepare callback. It also makes sense to remove can_sleep because it was also removed from deactivate_urbs() signature in [3] so we benefit from more simplification. [1] commit 015618b9 ("ALSA: snd-usb: Fix URB cancellation at stream start") [2] commit e9ba389c ("ALSA: usb-audio: Fix scheduling-while-atomic bug in PCM capture stream") [3] commit ccc1696d ("ALSA: usb-audio: simplify endpoint deactivation code") Fixes: f8114f85 ("Revert "ALSA: usb-audio: Fix race at stopping the stream"") Signed-off-by:
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