[4.2.y-ckt stable] Patch "ALSA: hda - Loop interrupt handling until really cleared" has been added to the 4.2.y-ckt tree
Kamal Mostafa
kamal at canonical.com
Mon Mar 7 22:35:16 UTC 2016
This is a note to let you know that I have just added a patch titled
ALSA: hda - Loop interrupt handling until really cleared
to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue
This patch is scheduled to be released in version 4.2.8-ckt5.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
---8<------------------------------------------------------------
>From 791751490953ddf62e6e6141615658598ebea17f Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai at suse.de>
Date: Tue, 23 Feb 2016 15:54:47 +0100
Subject: ALSA: hda - Loop interrupt handling until really cleared
commit 473f414564528a819f0c2bb6b4bf26366b64c9ab upstream.
Currently the interrupt handler of HD-audio driver assumes that no irq
update is needed while processing the irq. But in reality, it has
been confirmed that the HW irq is issued even during the irq
handling. Since we clear the irq status at the beginning, process the
interrupt, then exits from the handler, the lately issued interrupt is
left untouched without being properly processed.
This patch changes the interrupt handler code to loop over the
check-and-process. The handler tries repeatedly as long as the IRQ
status are turned on, and either stream or CORB/RIRB is handled.
For checking the stream handling, snd_hdac_bus_handle_stream_irq()
returns a value indicating the stream indices bits. Other than that,
the change is only in the irq handler itself.
Reported-by: Libin Yang <libin.yang at linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
[ kamal: backport to 4.2-stable: context ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
include/sound/hdaudio.h | 2 +-
sound/hda/hdac_controller.c | 7 ++++++-
sound/pci/hda/hda_controller.c | 47 +++++++++++++++++++++++-------------------
3 files changed, 33 insertions(+), 23 deletions(-)
diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h
index 4caf1fd..772d137 100644
--- a/include/sound/hdaudio.h
+++ b/include/sound/hdaudio.h
@@ -343,7 +343,7 @@ void snd_hdac_bus_enter_link_reset(struct hdac_bus *bus);
void snd_hdac_bus_exit_link_reset(struct hdac_bus *bus);
void snd_hdac_bus_update_rirb(struct hdac_bus *bus);
-void snd_hdac_bus_handle_stream_irq(struct hdac_bus *bus, unsigned int status,
+int snd_hdac_bus_handle_stream_irq(struct hdac_bus *bus, unsigned int status,
void (*ack)(struct hdac_bus *,
struct hdac_stream *));
diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
index b5a17cb..8c48623 100644
--- a/sound/hda/hdac_controller.c
+++ b/sound/hda/hdac_controller.c
@@ -426,18 +426,22 @@ EXPORT_SYMBOL_GPL(snd_hdac_bus_stop_chip);
* @bus: HD-audio core bus
* @status: INTSTS register value
* @ask: callback to be called for woken streams
+ *
+ * Returns the bits of handled streams, or zero if no stream is handled.
*/
-void snd_hdac_bus_handle_stream_irq(struct hdac_bus *bus, unsigned int status,
+int snd_hdac_bus_handle_stream_irq(struct hdac_bus *bus, unsigned int status,
void (*ack)(struct hdac_bus *,
struct hdac_stream *))
{
struct hdac_stream *azx_dev;
u8 sd_status;
+ int handled = 0;
list_for_each_entry(azx_dev, &bus->stream_list, list) {
if (status & azx_dev->sd_int_sta_mask) {
sd_status = snd_hdac_stream_readb(azx_dev, SD_STS);
snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK);
+ handled |= 1 << azx_dev->index;
if (!azx_dev->substream || !azx_dev->running ||
!(sd_status & SD_INT_COMPLETE))
continue;
@@ -445,6 +449,7 @@ void snd_hdac_bus_handle_stream_irq(struct hdac_bus *bus, unsigned int status,
ack(bus, azx_dev);
}
}
+ return handled;
}
EXPORT_SYMBOL_GPL(snd_hdac_bus_handle_stream_irq);
diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c
index 4013af3..1091b7a 100644
--- a/sound/pci/hda/hda_controller.c
+++ b/sound/pci/hda/hda_controller.c
@@ -930,6 +930,8 @@ irqreturn_t azx_interrupt(int irq, void *dev_id)
struct azx *chip = dev_id;
struct hdac_bus *bus = azx_bus(chip);
u32 status;
+ bool active, handled = false;
+ int repeat = 0; /* count for avoiding endless loop */
#ifdef CONFIG_PM
if (azx_has_pm_runtime(chip))
@@ -939,33 +941,36 @@ irqreturn_t azx_interrupt(int irq, void *dev_id)
spin_lock(&bus->reg_lock);
- if (chip->disabled) {
- spin_unlock(&bus->reg_lock);
- return IRQ_NONE;
- }
-
- status = azx_readl(chip, INTSTS);
- if (status == 0 || status == 0xffffffff) {
- spin_unlock(&bus->reg_lock);
- return IRQ_NONE;
- }
+ if (chip->disabled)
+ goto unlock;
- snd_hdac_bus_handle_stream_irq(bus, status, stream_update);
+ do {
+ status = azx_readl(chip, INTSTS);
+ if (status == 0 || status == 0xffffffff)
+ break;
- /* clear rirb int */
- status = azx_readb(chip, RIRBSTS);
- if (status & RIRB_INT_MASK) {
- if (status & RIRB_INT_RESPONSE) {
- if (chip->driver_caps & AZX_DCAPS_RIRB_PRE_DELAY)
- udelay(80);
- snd_hdac_bus_update_rirb(bus);
+ handled = true;
+ active = false;
+ if (snd_hdac_bus_handle_stream_irq(bus, status, stream_update))
+ active = true;
+
+ /* clear rirb int */
+ status = azx_readb(chip, RIRBSTS);
+ if (status & RIRB_INT_MASK) {
+ active = true;
+ if (status & RIRB_INT_RESPONSE) {
+ if (chip->driver_caps & AZX_DCAPS_RIRB_PRE_DELAY)
+ udelay(80);
+ snd_hdac_bus_update_rirb(bus);
+ }
+ azx_writeb(chip, RIRBSTS, RIRB_INT_MASK);
}
- azx_writeb(chip, RIRBSTS, RIRB_INT_MASK);
- }
+ } while (active && ++repeat < 10);
+ unlock:
spin_unlock(&bus->reg_lock);
- return IRQ_HANDLED;
+ return IRQ_RETVAL(handled);
}
EXPORT_SYMBOL_GPL(azx_interrupt);
--
2.7.0
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