Re: [PATCH v5 11/17] media: qcom: camss: Allow clocks vfeN vfe_liteN or vfe_lite

[Bryan O'Donoghue <bryan.odonoghue@linaro.org>]

On 25/09/2023 08:10, Hans Verkuil wrote:
> On 11/09/2023 15:14, Bryan O'Donoghue wrote:
>> The number of Video Front End - VFE or Image Front End - IFE supported
>> with new SoCs can vary both for the full and lite cases.
>>
>> For example sdm845 has one vfe_lite and two vfe interfaces with the vfe
>> clock called simply "vfe_lite" with no integer postfix. sc8280xp has four
>> vfe and four vfe lite blocks.
>>
>> At the moment we declare vfe_lite0 and vfe_lite1 for sm8250 but never set
>> those clocks because we don't match the strings.
>>
>> We need to support the following clock name formats
>>
>> - vfeN
>> - vfe_liteN
>> - vfe_lite
>>
>> with N being any reasonably sized integer.
>>
>> There are two sites in this code which need to do the same thing,
>> constructing and matching strings with the pattern above, so encapsulate
>> the logic in one function.
>>
>> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
>> ---
>>   drivers/media/platform/qcom/camss/camss-vfe.c | 22 ++++++++++++++-----
>>   1 file changed, 16 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/media/platform/qcom/camss/camss-vfe.c b/drivers/media/platform/qcom/camss/camss-vfe.c
>> index db8f68819ded9..f3cf387e4907e 100644
>> --- a/drivers/media/platform/qcom/camss/camss-vfe.c
>> +++ b/drivers/media/platform/qcom/camss/camss-vfe.c
>> @@ -431,6 +431,20 @@ void vfe_isr_reset_ack(struct vfe_device *vfe)
>>   	complete(&vfe->reset_complete);
>>   }
>>   
>> +static int vfe_match_clock_names(struct vfe_device *vfe,
>> +				 struct camss_clock *clock)
>> +{
>> +	char vfe_name[6]; /* vfeXX\0 */
>> +	char vfe_lite_name[11]; /* vfe_liteXX\0 */
>> +
>> +	snprintf(vfe_name, sizeof(vfe_name), "vfe%d", vfe->id);
>> +	snprintf(vfe_lite_name, sizeof(vfe_lite_name), "vfe_lite%d", vfe->id);
>> +
>> +	return (!strcmp(clock->name, vfe_name) ||
>> +		!strcmp(clock->name, vfe_lite_name) ||
>> +		!strcmp(clock->name, "vfe_lite"));
>> +}
> 
> I'm getting this compiler warning:
> 
> drivers/media/platform/qcom/camss/camss-vfe.c: In function 'vfe_match_clock_names':
> drivers/media/platform/qcom/camss/camss-vfe.c:483:52: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=]
>    483 |         snprintf(vfe_name, sizeof(vfe_name), "vfe%d", vfe->id);
>        |                                                    ^
> 
> Since vfe->id is a u8 I would just increase both the vfe_name and vfe_lite_name
> sizes by 1.
> 
> Regards,
> 
> 	Hans
> 

Hmm. True.

Maximum value of VFE id is 255 @ u8

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bod