[PATCH v2 2/4] iio: light: rohm-bu27034: Fix infinite delay on error

From: Matti Vaittinen <[email protected]>

When reading an integration-time fails, the code will use error code to
compute the sleep time.

Fix this by using the smallest integration time as a default if
reading fails.

Fixes: e52afbd61039 ("iio: light: ROHM BU27034 Ambient Light Sensor")
Signed-off-by: Matti Vaittinen <[email protected]>

---
Revision history:
v1 => v2:
 - Moved Fixes before SOB
 - Clarified units for the smallest integration time as suggested by Andy
---
 drivers/iio/light/rohm-bu27034.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/iio/light/rohm-bu27034.c b/drivers/iio/light/rohm-bu27034.c
index f9a421618406..cb2afddc75f6 100644
--- a/drivers/iio/light/rohm-bu27034.c
+++ b/drivers/iio/light/rohm-bu27034.c
@@ -137,6 +137,7 @@ static const struct iio_gain_sel_pair bu27034_gains[] = {
 #define BU27034_MEAS_MODE_200MS		2
 #define BU27034_MEAS_MODE_400MS		4
 
+#define BU27034_INT_TIME_US_MIN (55 * USEC_PER_MSEC)
 static const struct iio_itime_sel_mul bu27034_itimes[] = {
 	GAIN_SCALE_ITIME_US(400000, BU27034_MEAS_MODE_400MS, 8),
 	GAIN_SCALE_ITIME_US(200000, BU27034_MEAS_MODE_200MS, 4),
@@ -1162,6 +1163,15 @@ static int bu27034_buffer_thread(void *arg)
 	data = iio_priv(idev);
 
 	wait_ms = bu27034_get_int_time(data);
+
+	/*
+	 * If reading the integration time fails, default to the minimum so we
+	 * don't lose samples. This may waste CPU cycles, but as a hardening
+	 * against theoretical, once-in-a-blue-moon error, this should be Ok.
+	 */
+	if (wait_ms < 0)
+		wait_ms = BU27034_INT_TIME_US_MIN;
+
 	wait_ms /= 1000;
 
 	wait_ms -= BU27034_MEAS_WAIT_PREMATURE_MS;
-- 
2.55.0

-----BEGIN PGP SIGNATURE-----

iQEzBAEBCgAdFiEEIx+f8wZb28fLKEhTeFA3/03aocUFAmqRO3QACgkQeFA3/03a
ocWprwgAuMW+8SNHkdRXkBD2VPg+Vc/UYBgwtxBoLA9zia1FuMgwyslAaLb42L67
O3tsgKScB0y6RZ2gIBFw+d0Jpd8/3vTrRa3ai12ueHzAbqUJu+EtXZnKFPRKCrJQ
pmcEFhwPaDeDdkuEMPmk+9gFE9CgZuKYbCc6tAZFQ1Y1MAjO9C4Y/SVHp7E+MH+3
FJlATNWkjaUc0Mb4XufFR8B+enfBliNt2Y0lyyHsNbWUy0+/4do5nDiWMN0JjVXh
F5xc5g/xYRTDBTjT4JkRv71tUpjFXzaZkHsLzXO2s3TBAbYksIkgvAmemR2PFbqS
rqX9OY7PdsnyDuFNHKuz0tZyT7ordQ==
=bbX1
-----END PGP SIGNATURE-----