On 16/10/2024 13:24, Mauro Carvalho Chehab wrote:
> Em Wed, 16 Oct 2024 12:57:53 +0200
> Hans Verkuil <hverkuil@xxxxxxxxx> escreveu:
>
>> On 16/10/2024 12:22, Mauro Carvalho Chehab wrote:
>>> Currently, adv76xx_log_status() reads some date using
>>> io_read() which may return negative values. The current logi
>>> doesn't check such errors, causing colorspace to be reported
>>> on a wrong way at adv76xx_log_status().
>>>
>>> If I/O error happens there, print a different message, instead
>>> of reporting bogus messages to userspace.
>>>
>>> Fixes: 54450f591c99 ("[media] adv7604: driver for the Analog Devices ADV7604 video decoder")
>>> Cc: stable@xxxxxxxxxxxxxxx
>>
>> Not really a fix since this would just affect logging for debugging
>> purposes. I would personally just drop the Fixes and Cc tag.
>
> The issue is on a VIDIOC_ ioctl, so part of media API. Ok, this is
> used only for debugging purposes and should, instead be implemented
> via debugfs, etc, but, in summary: it is what it is: part of the V4L2
> uAPI.
The ioctl, yes, but what it logs to the kernel log isn't part of the ABI.
That can change.
I think it is overkill to send this to stable for an old chip that almost
nobody uses, and that requires an i2c read to go wrong for it to produce
a wrong debug message. It seems an unnecessary waste of time.
>
> -
>
> Now, the question about what should have Fixes: tag and what
> shouldn't is a different matter. I've saw long discussions about
> that at the kernel mailing lists. In the particular case of y2038,
> I'm pretty sure I saw some of them with Fixes tag on it.
But patch 13/13 doesn't affect the operation either, again it is just
an incorrect log message that can only go wrong if Pulse-Eight still
sells that device in 2038 with a firmware build date >= 2038. And v6.12
is guaranteed to be EOL in 2038 :-)
Regards,
Hans
>
>>
>>> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
>>
>> Reviewed-by: Hans Verkuil <hverkuil@xxxxxxxxx>
>>
>> Regards,
>>
>> Hans
>>
>>> ---
>>> drivers/media/i2c/adv7604.c | 26 +++++++++++++++++---------
>>> 1 file changed, 17 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/drivers/media/i2c/adv7604.c b/drivers/media/i2c/adv7604.c
>>> index 48230d5109f0..272945a878b3 100644
>>> --- a/drivers/media/i2c/adv7604.c
>>> +++ b/drivers/media/i2c/adv7604.c
>>> @@ -2519,10 +2519,10 @@ static int adv76xx_log_status(struct v4l2_subdev *sd)
>>> const struct adv76xx_chip_info *info = state->info;
>>> struct v4l2_dv_timings timings;
>>> struct stdi_readback stdi;
>>> - u8 reg_io_0x02 = io_read(sd, 0x02);
>>> + int ret;
>>> + u8 reg_io_0x02;
>>> u8 edid_enabled;
>>> u8 cable_det;
>>> -
>>> static const char * const csc_coeff_sel_rb[16] = {
>>> "bypassed", "YPbPr601 -> RGB", "reserved", "YPbPr709 -> RGB",
>>> "reserved", "RGB -> YPbPr601", "reserved", "RGB -> YPbPr709",
>>> @@ -2621,13 +2621,21 @@ static int adv76xx_log_status(struct v4l2_subdev *sd)
>>> v4l2_info(sd, "-----Color space-----\n");
>>> v4l2_info(sd, "RGB quantization range ctrl: %s\n",
>>> rgb_quantization_range_txt[state->rgb_quantization_range]);
>>> - v4l2_info(sd, "Input color space: %s\n",
>>> - input_color_space_txt[reg_io_0x02 >> 4]);
>>> - v4l2_info(sd, "Output color space: %s %s, alt-gamma %s\n",
>>> - (reg_io_0x02 & 0x02) ? "RGB" : "YCbCr",
>>> - (((reg_io_0x02 >> 2) & 0x01) ^ (reg_io_0x02 & 0x01)) ?
>>> - "(16-235)" : "(0-255)",
>>> - (reg_io_0x02 & 0x08) ? "enabled" : "disabled");
>>> +
>>> + ret = io_read(sd, 0x02);
>>> + if (ret < 0) {
>>> + v4l2_info(sd, "Can't read Input/Output color space\n");
>>> + } else {
>>> + reg_io_0x02 = ret;
>>> +
>>> + v4l2_info(sd, "Input color space: %s\n",
>>> + input_color_space_txt[reg_io_0x02 >> 4]);
>>> + v4l2_info(sd, "Output color space: %s %s, alt-gamma %s\n",
>>> + (reg_io_0x02 & 0x02) ? "RGB" : "YCbCr",
>>> + (((reg_io_0x02 >> 2) & 0x01) ^ (reg_io_0x02 & 0x01)) ?
>>> + "(16-235)" : "(0-255)",
>>> + (reg_io_0x02 & 0x08) ? "enabled" : "disabled");
>>> + }
>>> v4l2_info(sd, "Color space conversion: %s\n",
>>> csc_coeff_sel_rb[cp_read(sd, info->cp_csc) >> 4]);
>>>
>>
>
>
>
> Thanks,
> Mauro
