[PATCH] ASoC: codecs: Fix WCD_MBHC_HPH_PA_EN usage

From: Christophe JAILLET
Date: Sun Oct 17 2021 - 03:31:32 EST


'hphpa_on' is known to be false, so the if block at the end of the function
is dead code.

Turn it into a meaningful code by having 'hphpa_on' be static. Use is as a
flip-flop variable.

Fixes: 0e5c9e7ff899 ("ASoC: codecs: wcd: add multi button Headset detection support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
The purpose of this patch is not to be correct (!) but to draw attention
on several points:
- in 'wcd_mbhc_adc_hs_rem_irq()', the "if (hphpa_on)" path is dead code
because 'hphpa_on' is known to be false
- What is this magic number '3'?
All 'wcd_mbhc_read_field()' look for 0 or non-0
- a 'mutex_[un]lock()' in an IRQ handler looks spurious to me

Instead of this (likely broken) patch, it is likely that something is
missing elsewhere. Maybe in 'wcd_mbhc_adc_hs_ins_irq()'.
I also guess that 'hphpa_on' should be read for somewhere else.
---
sound/soc/codecs/wcd-mbhc-v2.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sound/soc/codecs/wcd-mbhc-v2.c b/sound/soc/codecs/wcd-mbhc-v2.c
index 405128ccb4b0..783d8c35bc1b 100644
--- a/sound/soc/codecs/wcd-mbhc-v2.c
+++ b/sound/soc/codecs/wcd-mbhc-v2.c
@@ -1176,7 +1176,7 @@ static irqreturn_t wcd_mbhc_adc_hs_rem_irq(int irq, void *data)
struct wcd_mbhc *mbhc = data;
unsigned long timeout;
int adc_threshold, output_mv, retry = 0;
- bool hphpa_on = false;
+ static bool hphpa_on = false;

mutex_lock(&mbhc->lock);
timeout = jiffies + msecs_to_jiffies(WCD_FAKE_REMOVAL_MIN_PERIOD_MS);
@@ -1212,6 +1212,9 @@ static irqreturn_t wcd_mbhc_adc_hs_rem_irq(int irq, void *data)

if (hphpa_on) {
hphpa_on = false;
+ wcd_mbhc_write_field(mbhc, WCD_MBHC_HPH_PA_EN, 0);
+ } else {
+ hphpa_on = true;
wcd_mbhc_write_field(mbhc, WCD_MBHC_HPH_PA_EN, 3);
}
exit:
--
2.30.2