[PATCH] iio: sx9310: Fix write_.._debounce()

[PATCH] iio: sx9310: Fix write_.._debounce()

[Gwendal Grignou]

Check input to be sure it matches Semtech sx9310 specification and
can fit into debounce register.
Compare argument writen to thresh_.._period with read from same
sysfs attribute:

Before:                   Afer:
write   |  read           write   |  read
-1      |     8           -1 fails: -EINVAL
0       |     8           0       |     0
1       |     0           1       |     0
2..15   |  2^log2(N)      2..15   |  2^log2(N)
16      |     0           >= 16 fails: -EINVAL

Fixes: 1b6872015f0b ("iio: sx9310: Support setting debounce values")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Cc: stable@vger.kernel.org
---
 drivers/iio/proximity/sx9310.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
index 578d8841c5398..e5a756f4afa2b 100644
--- a/drivers/iio/proximity/sx9310.c
+++ b/drivers/iio/proximity/sx9310.c
@@ -764,7 +764,11 @@ static int sx9310_write_far_debounce(struct sx9310_data *data, int val)
 	int ret;
 	unsigned int regval;
 
-	val = ilog2(val);
+	if (val > 0)
+		val = ilog2(val);
+	if (!FIELD_FIT(SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK, val))
+		return -EINVAL;
+
 	regval = FIELD_PREP(SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK, val);
 
 	mutex_lock(&data->mutex);
@@ -781,7 +785,11 @@ static int sx9310_write_close_debounce(struct sx9310_data *data, int val)
 	int ret;
 	unsigned int regval;
 
-	val = ilog2(val);
+	if (val > 0)
+		val = ilog2(val);
+	if (!FIELD_FIT(SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK, val))
+		return -EINVAL;
+
 	regval = FIELD_PREP(SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK, val);
 
 	mutex_lock(&data->mutex);
-- 
2.31.0.291.g576ba9dcdaf-goog

Re: [PATCH] iio: sx9310: Fix write_.._debounce()

[Stephen Boyd]

Quoting Gwendal Grignou (2021-03-31 11:22:22)
> Check input to be sure it matches Semtech sx9310 specification and
> can fit into debounce register.
> Compare argument writen to thresh_.._period with read from same
> sysfs attribute:
> 
> Before:                   Afer:
> write   |  read           write   |  read
> -1      |     8           -1 fails: -EINVAL
> 0       |     8           0       |     0
> 1       |     0           1       |     0
> 2..15   |  2^log2(N)      2..15   |  2^log2(N)
> 16      |     0           >= 16 fails: -EINVAL
> 
> Fixes: 1b6872015f0b ("iio: sx9310: Support setting debounce values")
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> Cc: stable@vger.kernel.org
> ---

Reviewed-by: Stephen Boyd <swboyd@chromium.org>

Re: [PATCH] iio: sx9310: Fix write_.._debounce()

[Jonathan Cameron]

On Wed, 31 Mar 2021 12:49:18 -0700
Stephen Boyd <swboyd@chromium.org> wrote:

> Quoting Gwendal Grignou (2021-03-31 11:22:22)
> > Check input to be sure it matches Semtech sx9310 specification and
> > can fit into debounce register.
> > Compare argument writen to thresh_.._period with read from same
> > sysfs attribute:
> > 
> > Before:                   Afer:
> > write   |  read           write   |  read
> > -1      |     8           -1 fails: -EINVAL
> > 0       |     8           0       |     0
> > 1       |     0           1       |     0
> > 2..15   |  2^log2(N)      2..15   |  2^log2(N)
> > 16      |     0           >= 16 fails: -EINVAL
> > 
> > Fixes: 1b6872015f0b ("iio: sx9310: Support setting debounce values")
> > Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> > Cc: stable@vger.kernel.org
> > ---  
> 
> Reviewed-by: Stephen Boyd <swboyd@chromium.org>

Applied to the fixes-togreg branch of iio.git.

Thanks,

Jonathan