kernel 5.19.12

1 files changed, 200 insertions, 0 deletions

diff --git a/SOURCES/ALSA:-usb-audio:-Split-endpoint-setups-for-hw_params-and-prepare.patch b/SOURCES/ALSA:-usb-audio:-Split-endpoint-setups-for-hw_params-and-prepare.patch
new file mode 100644
index 0000000..d23deb0
--- /dev/null
+++ b/SOURCES/ALSA:-usb-audio:-Split-endpoint-setups-for-hw_params-and-prepare.patch
@@ -0,0 +1,200 @@
+From 271f862ebc60b3a7ff1563654eb33cd4571c66aa Mon Sep 17 00:00:00 2001
+From: Takashi Iwai <tiwai@suse.de>
+Date: Thu, 1 Sep 2022 14:41:36 +0200
+Subject: ALSA: usb-audio: Split endpoint setups for hw_params and prepare
+
+commit ff878b408a03bef5d610b7e2302702e16a53636e upstream.
+
+One of the former changes for the endpoint management was the more
+consistent setup of endpoints at hw_params.
+snd_usb_endpoint_configure() is a single function that does the full
+setup, and it's called from both PCM hw_params and prepare callbacks.
+Although the EP setup at the prepare phase is usually skipped (by
+checking need_setup flag), it may be still effective in some cases
+like suspend/resume that requires the interface setup again.
+
+As it's a full and single setup, the invocation of
+snd_usb_endpoint_configure() includes not only the USB interface setup
+but also the buffer release and allocation.  OTOH, doing the buffer
+release and re-allocation at PCM prepare phase is rather superfluous,
+and better to be done only in the hw_params phase.
+
+For those optimizations, this patch splits the endpoint setup to two
+phases: snd_usb_endpoint_set_params() and snd_usb_endpoint_prepare(),
+to be called from hw_params and from prepare, respectively.
+
+Note that this patch changes the driver operation slightly,
+effectively moving the USB interface setup again to PCM prepare stage
+instead of hw_params stage, while the buffer allocation and such
+initializations are still done at hw_params stage.
+
+And, the change of the USB interface setup timing (moving to prepare)
+gave an interesting "fix", too: it was reported that the recent
+kernels caused silent output at the beginning on playbacks on some
+devices on Android, and this change casually fixed the regression.
+It seems that those devices are picky about the sample rate change (or
+the interface change?), and don't follow the too immediate rate
+changes.
+
+Meanwhile, Android operates the PCM in the following order:
+- open, then hw_params with the possibly highest sample rate
+- close without prepare
+- re-open, hw_params with the normal sample rate
+- prepare, and start streaming
+This procedure ended up the hw_params twice with different rates, and
+because the recent kernel did set up the sample rate twice one and
+after, it screwed up the device.  OTOH, the earlier kernels didn't set
+up the USB interface at hw_params, hence this problem didn't appear.
+
+Now, with this patch, the USB interface setup is again back to the
+prepare phase, and it works around the problem automagically.
+Although we should address the sample rate problem in a more solid
+way in future, let's keep things working as before for now.
+
+Fixes: bf6313a0ff76 ("ALSA: usb-audio: Refactor endpoint management")
+Cc: <stable@vger.kernel.org>
+Reported-by: chihhao chen <chihhao.chen@mediatek.com>
+Link: https://lore.kernel.org/r/87e6d6ae69d68dc588ac9acc8c0f24d6188375c3.camel@mediatek.com
+Link: https://lore.kernel.org/r/20220901124136.4984-1-tiwai@suse.de
+Signed-off-by: Takashi Iwai <tiwai@suse.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ sound/usb/endpoint.c | 23 +++++++++--------------
+ sound/usb/endpoint.h |  6 ++++--
+ sound/usb/pcm.c      | 14 ++++++++++----
+ 3 files changed, 23 insertions(+), 20 deletions(-)
+
+diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
+index f9c921683948d..ff9c7bbbc43fe 100644
+--- a/sound/usb/endpoint.c
++++ b/sound/usb/endpoint.c
+@@ -758,7 +758,8 @@ bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip,
+  * The endpoint needs to be closed via snd_usb_endpoint_close() later.
+  *
+  * Note that this function doesn't configure the endpoint.  The substream
+- * needs to set it up later via snd_usb_endpoint_configure().
++ * needs to set it up later via snd_usb_endpoint_set_params() and
++ * snd_usb_endpoint_prepare().
+  */
+ struct snd_usb_endpoint *
+ snd_usb_endpoint_open(struct snd_usb_audio *chip,
+@@ -1290,12 +1291,13 @@ out_of_memory:
+ /*
+  * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
+  *
++ * It's called either from hw_params callback.
+  * Determine the number of URBs to be used on this endpoint.
+  * An endpoint must be configured before it can be started.
+  * An endpoint that is already running can not be reconfigured.
+  */
+-static int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
+-				       struct snd_usb_endpoint *ep)
++int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
++				struct snd_usb_endpoint *ep)
+ {
+ 	const struct audioformat *fmt = ep->cur_audiofmt;
+ 	int err;
+@@ -1378,18 +1380,18 @@ static int init_sample_rate(struct snd_usb_audio *chip,
+ }
+ 
+ /*
+- * snd_usb_endpoint_configure: Configure the endpoint
++ * snd_usb_endpoint_prepare: Prepare the endpoint
+  *
+  * This function sets up the EP to be fully usable state.
+- * It's called either from hw_params or prepare callback.
++ * It's called either from prepare callback.
+  * The function checks need_setup flag, and performs nothing unless needed,
+  * so it's safe to call this multiple times.
+  *
+  * This returns zero if unchanged, 1 if the configuration has changed,
+  * or a negative error code.
+  */
+-int snd_usb_endpoint_configure(struct snd_usb_audio *chip,
+-			       struct snd_usb_endpoint *ep)
++int snd_usb_endpoint_prepare(struct snd_usb_audio *chip,
++			     struct snd_usb_endpoint *ep)
+ {
+ 	bool iface_first;
+ 	int err = 0;
+@@ -1410,9 +1412,6 @@ int snd_usb_endpoint_configure(struct snd_usb_audio *chip,
+ 			if (err < 0)
+ 				goto unlock;
+ 		}
+-		err = snd_usb_endpoint_set_params(chip, ep);
+-		if (err < 0)
+-			goto unlock;
+ 		goto done;
+ 	}
+ 
+@@ -1440,10 +1439,6 @@ int snd_usb_endpoint_configure(struct snd_usb_audio *chip,
+ 	if (err < 0)
+ 		goto unlock;
+ 
+-	err = snd_usb_endpoint_set_params(chip, ep);
+-	if (err < 0)
+-		goto unlock;
+-
+ 	err = snd_usb_select_mode_quirk(chip, ep->cur_audiofmt);
+ 	if (err < 0)
+ 		goto unlock;
+diff --git a/sound/usb/endpoint.h b/sound/usb/endpoint.h
+index 6a9af04cf175a..e67ea28faa54f 100644
+--- a/sound/usb/endpoint.h
++++ b/sound/usb/endpoint.h
+@@ -17,8 +17,10 @@ snd_usb_endpoint_open(struct snd_usb_audio *chip,
+ 		      bool is_sync_ep);
+ void snd_usb_endpoint_close(struct snd_usb_audio *chip,
+ 			    struct snd_usb_endpoint *ep);
+-int snd_usb_endpoint_configure(struct snd_usb_audio *chip,
+-			       struct snd_usb_endpoint *ep);
++int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
++				struct snd_usb_endpoint *ep);
++int snd_usb_endpoint_prepare(struct snd_usb_audio *chip,
++			     struct snd_usb_endpoint *ep);
+ int snd_usb_endpoint_get_clock_rate(struct snd_usb_audio *chip, int clock);
+ 
+ bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip,
+diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
+index e692ae04436a5..02035b545f9dd 100644
+--- a/sound/usb/pcm.c
++++ b/sound/usb/pcm.c
+@@ -443,17 +443,17 @@ static int configure_endpoints(struct snd_usb_audio *chip,
+ 		if (stop_endpoints(subs, false))
+ 			sync_pending_stops(subs);
+ 		if (subs->sync_endpoint) {
+-			err = snd_usb_endpoint_configure(chip, subs->sync_endpoint);
++			err = snd_usb_endpoint_prepare(chip, subs->sync_endpoint);
+ 			if (err < 0)
+ 				return err;
+ 		}
+-		err = snd_usb_endpoint_configure(chip, subs->data_endpoint);
++		err = snd_usb_endpoint_prepare(chip, subs->data_endpoint);
+ 		if (err < 0)
+ 			return err;
+ 		snd_usb_set_format_quirk(subs, subs->cur_audiofmt);
+ 	} else {
+ 		if (subs->sync_endpoint) {
+-			err = snd_usb_endpoint_configure(chip, subs->sync_endpoint);
++			err = snd_usb_endpoint_prepare(chip, subs->sync_endpoint);
+ 			if (err < 0)
+ 				return err;
+ 		}
+@@ -551,7 +551,13 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
+ 	subs->cur_audiofmt = fmt;
+ 	mutex_unlock(&chip->mutex);
+ 
+-	ret = configure_endpoints(chip, subs);
++	if (subs->sync_endpoint) {
++		ret = snd_usb_endpoint_set_params(chip, subs->sync_endpoint);
++		if (ret < 0)
++			goto unlock;
++	}
++
++	ret = snd_usb_endpoint_set_params(chip, subs->data_endpoint);
+ 
+  unlock:
+ 	if (ret < 0)
+-- 
+cgit 
+