ASoC: da7219: Patches related to a spurious AAD IRQ

Merge series from Dmytro Maluka <dmy@semihalf.com>:

This series includes 2 patches related to (but not fixing) the following
I2C failure which occurs sometimes during system suspend or resume and
indicates a problem with a spurious DA7219 interrupt:

[  355.876211] i2c_designware i2c_designware.3: Transfer while suspended
[  355.876245] WARNING: CPU: 2 PID: 3576 at drivers/i2c/busses/i2c-designware-master.c:570 i2c_dw_xfer+0x411/0x440
...
[  355.876462] Call Trace:
[  355.876468]  <TASK>
[  355.876475]  ? update_load_avg+0x1b3/0x615
[  355.876484]  __i2c_transfer+0x101/0x1d8
[  355.876494]  i2c_transfer+0x74/0x10d
[  355.876504]  regmap_i2c_read+0x6a/0x9c
[  355.876513]  _regmap_raw_read+0x179/0x223
[  355.876521]  regmap_raw_read+0x1e1/0x28e
[  355.876527]  regmap_bulk_read+0x17d/0x1ba
[  355.876532]  ? __wake_up+0xed/0x1bb
[  355.876542]  da7219_aad_irq_thread+0x54/0x2c9 [snd_soc_da7219 5fb8ebb2179cf2fea29af090f3145d68ed8e2184]
[  355.876556]  irq_thread+0x13c/0x231
[  355.876563]  ? irq_forced_thread_fn+0x5f/0x5f
[  355.876570]  ? irq_thread_fn+0x4d/0x4d
[  355.876576]  kthread+0x13a/0x152
[  355.876581]  ? synchronize_irq+0xc3/0xc3
[  355.876587]  ? kthread_blkcg+0x31/0x31
[  355.876592]  ret_from_fork+0x1f/0x30
[  355.876601]  </TASK>

This log shows that DA7219 AAD interrupt handler da7219_aad_irq_thread()
is unexpectedly running when DA7219 is suspended and should not generate
interrupts. As a result, the IRQ handler is trying to read AAD IRQ event
status over I2C and is hitting the I2C driver "Transfer while suspended"
failure.

Patch #1 adds synchronize_irq() when suspending DA7219, to prevent the
IRQ handler from running after suspending if there is a pending IRQ
generated before suspending. With this patch the above failure is still
reproducible, so this patch does not fix any real observed issue so far,
but at least is useful for confirming that the above issue is not caused
by a pending IRQ but rather looks like a DA7219 hardware issue with an
unexpectedly generated IRQ.

Patch #2 does not fix the above issue either, but it prevents its
potentially harmful side effects. With the existing code, if the issue
occurs and the IRQ handler fails to read the AAD IRQ events status over
I2C, it does not check that and tries to use the garbage uninitialized
value of the events status, potentially reporting bogus events. This
patch fixes that by adding missing error checking.

In fact I'm sending these patches not only to submit them for review but
also to ask Renesas folks for any hints on a possible cause of the
described DA7219 issue (AAD interrupts spuriously firing after jack
detection is already disabled) or how to debug it further.

1 files changed, 9 insertions, 3 deletions

diff --git a/sound/soc/codecs/da7219-aad.c b/sound/soc/codecs/da7219-aad.c
index c65256bd526d..581b334a6631 100644
--- a/sound/soc/codecs/da7219-aad.c
+++ b/sound/soc/codecs/da7219-aad.c
@@ -361,11 +361,15 @@ static irqreturn_t da7219_aad_irq_thread(int irq, void *data)
 	struct da7219_priv *da7219 = snd_soc_component_get_drvdata(component);
 	u8 events[DA7219_AAD_IRQ_REG_MAX];
 	u8 statusa;
-	int i, report = 0, mask = 0;
+	int i, ret, report = 0, mask = 0;
 
 	/* Read current IRQ events */
-	regmap_bulk_read(da7219->regmap, DA7219_ACCDET_IRQ_EVENT_A,
-			 events, DA7219_AAD_IRQ_REG_MAX);
+	ret = regmap_bulk_read(da7219->regmap, DA7219_ACCDET_IRQ_EVENT_A,
+			       events, DA7219_AAD_IRQ_REG_MAX);
+	if (ret) {
+		dev_warn_ratelimited(component->dev, "Failed to read IRQ events: %d\n", ret);
+		return IRQ_NONE;
+	}
 
 	if (!events[DA7219_AAD_IRQ_REG_A] && !events[DA7219_AAD_IRQ_REG_B])
 		return IRQ_NONE;
@@ -944,6 +948,8 @@ void da7219_aad_suspend(struct snd_soc_component *component)
 			}
 		}
 	}
+
+	synchronize_irq(da7219_aad->irq);
 }
 
 void da7219_aad_resume(struct snd_soc_component *component)