Add logic to wm97xx_read_aux_adc() to retry reading the adc if the
sample failed. This could occur if the previous sample was still in
the return register or the sample timed-out. Also avoid a pathologic
failure mode by disabling the digitizer and returning -EBUSY after 5
retries.
Signed-off-by: Eric Millbrandt <emillbrandt@xxxxxxxxxxxxxxxx>
---
drivers/input/touchscreen/wm97xx-core.c | 12 ++++++++++--
1 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/input/touchscreen/wm97xx-core.c b/drivers/input/touchscreen/wm97xx-core.c
index cbfef1e..b376cee 100644
--- a/drivers/input/touchscreen/wm97xx-core.c
+++ b/drivers/input/touchscreen/wm97xx-core.c
@@ -125,6 +125,8 @@ int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel)
{
int power_adc = 0, auxval;
u16 power = 0;
+ int rc = 0;
+ int timeout = 0;
/* get codec */
mutex_lock(&wm->codec_mutex);
@@ -143,7 +145,10 @@ int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel)
/* Turn polling mode on to read AUX ADC */
wm->pen_probably_down = 1;
- wm->codec->poll_sample(wm, adcsel, &auxval);
+
+ while (rc != RC_VALID && timeout++ < 5) {
+ rc = wm->codec->poll_sample(wm, adcsel, &auxval);
+ }
if (power_adc)
wm97xx_reg_write(wm, AC97_EXTENDED_MID, power | 0x8000);
@@ -152,8 +157,11 @@ int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel)
wm->pen_probably_down = 0;
+ if (timeout >= 5)
+ wm->codec->dig_enable(wm, false);
+
mutex_unlock(&wm->codec_mutex);
- return auxval & 0xfff;
+ return (rc == RC_VALID ? auxval & 0xfff : -EBUSY);
}
EXPORT_SYMBOL_GPL(wm97xx_read_aux_adc);
--
1.6.3.1
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