The driver stores frame format settings supposed to be in line with hardware state in a device private structure. Since the driver initial submission, those settings are updated before they are actually applied on hardware. If an error occurs on device update, the stored settings my not reflect hardware state anymore and consecutive calls to .get_fmt() may return incorrect information. That in turn may affect ability of a bridge device to use correct DMA transfer settings if such incorrect informmation on active frame format returned by .get_fmt() is used.
Assuming a failed device update mean its state hasn't changed, update frame format related settings stored in the device private structure only after they are successfully applied so the stored values always reflect hardware state as closely as possible.
Fixes: 2f6e2404799a ("[media] SoC Camera: add driver for OV6650 sensor") Signed-off-by: Janusz Krzysztofik jmkrzyszt@gmail.com Cc: stable@vger.kernel.org --- drivers/media/i2c/ov6650.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/media/i2c/ov6650.c b/drivers/media/i2c/ov6650.c index b199332f62d7..65d43390dbeb 100644 --- a/drivers/media/i2c/ov6650.c +++ b/drivers/media/i2c/ov6650.c @@ -630,7 +630,6 @@ static int ov6650_s_fmt(struct v4l2_subdev *sd, struct v4l2_mbus_framefmt *mf) dev_err(&client->dev, "Pixel format not handled: 0x%x\n", code); return -EINVAL; } - priv->code = code;
if (code == MEDIA_BUS_FMT_Y8_1X8 || code == MEDIA_BUS_FMT_SBGGR8_1X8) { @@ -651,7 +650,6 @@ static int ov6650_s_fmt(struct v4l2_subdev *sd, struct v4l2_mbus_framefmt *mf) dev_dbg(&client->dev, "max resolution: CIF\n"); coma_mask |= COMA_QCIF; } - priv->half_scale = half_scale;
clkrc = CLKRC_12MHz; mclk = 12000000; @@ -669,8 +667,13 @@ static int ov6650_s_fmt(struct v4l2_subdev *sd, struct v4l2_mbus_framefmt *mf) ret = ov6650_reg_rmw(client, REG_COMA, coma_set, coma_mask); if (!ret) ret = ov6650_reg_write(client, REG_CLKRC, clkrc); - if (!ret) + if (!ret) { + priv->half_scale = half_scale; + ret = ov6650_reg_rmw(client, REG_COML, coml_set, coml_mask); + } + if (!ret) + priv->code = code;
return ret; }