Re: [PATCH master 3/3] common: boards: wolfvision: fix handling of overlays parameter

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 15.05.24 10:32, Michael Riesch wrote:
> Hi all,
> 
> On 5/15/24 10:00, Michael Riesch wrote:
>> If the char **overlays parameter to wolfvision_rk3568_detect_hw is NULL,
>> the overlay file names are not collected.
>>
>> If overlays points to a NULL pointer, it is initialized properly with
>> an empty string. This is convenient as the call to
>>     globalvar_set("of.overlay.filepattern", my_resulting_string);
>> that usually follows actually resets the global filepattern variable
>> from its default "*" to "". Thereby, a paradoxical situation in which no
>> extensions are detected but all available overlays are applied (due to "*")
>> is avoided.
>>
>> Nevertheless, it is still possible to pass an existing string to this
>> method and let the method append overlay file names.
>>
>> Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
>> ---
>>  common/boards/wolfvision/common.c | 5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/common/boards/wolfvision/common.c b/common/boards/wolfvision/common.c
>> index f483918cec..6cb76250dd 100644
>> --- a/common/boards/wolfvision/common.c
>> +++ b/common/boards/wolfvision/common.c
>> @@ -20,7 +20,7 @@ int wolfvision_apply_overlay(const struct wv_overlay *overlay, char **files)
>>  {
>>  	int ret;
>>  
>> -	if (overlay->filename) {
>> +	if (overlay->filename && files) {
>>  		if (*files) {
>>  			char *old = *files;
>>  			*files = basprintf("%s %s", old, overlay->filename);
>> @@ -115,6 +115,9 @@ int wolfvision_rk3568_detect_hw(const struct wv_rk3568_extension *extensions,
>>  	if (ret)
>>  		return ret;
>>  
>> +	if (overlays && !*overlays)
>> +		*overlays = basprintf("");
> 
> Hm, apparently this gives a compiler warning "warning: zero-length
> gnu_printf format string [-Wformat-zero-length]".
> 
> ... = basprintf("%s", ""); ???

xstrdup("")

> 
> Best regards,
> Michael
> 
>> +
>>  	for (i = 0; i < num_extensions; i++) {
>>  		const struct wv_rk3568_extension *extension = &extensions[i];
>>  		const struct wv_overlay *overlay;
>>
> 
> 

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