Re: [PATCH v3] drm/amd/display: fix type mismatch in CalculateDynamicMetadataParameters()

[Alex Hung <alex.hung@amd.com>]

Reviewed-by: Alex Hung <alex.hung@amd.com>

On 2/26/25 13:28, Vitaliy Shevtsov wrote:
> There is a type mismatch between what CalculateDynamicMetadataParameters()
> takes and what is passed to it. Currently this function accepts several
> args as signed long but it's called with unsigned integers and integer. On
> some systems where long is 32 bits and one of these unsigned int params is
> greater than INT_MAX it may cause passing input params as negative values.
> 
> Fix this by changing these argument types from long to unsigned int and to
> int respectively. Also this will align the function's definition with
> similar functions in other dcn* drivers.
> 
> Found by Linux Verification Center (linuxtesting.org) with Svace.
> 
> Fixes: 6725a88f88a7 ("drm/amd/display: Add DCN3 DML")
> Signed-off-by: Vitaliy Shevtsov <v.shevtsov@mt-integration.ru>
> ---
> v3: Update the description to include int in addition to unsigned int.
> v2: Change DynamicMetadataLinesBeforeActiveRequired type from unsigned int
>      to int as per Alex Hung's observation.
>      Add Fixes tag missed by chance.
> 
>   .../amd/display/dc/dml/dcn30/display_mode_vba_30.c   | 12 ++++++------
>   1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c b/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c
> index cee1b351e105..f1fe49401bc0 100644
> --- a/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c
> +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c
> @@ -281,10 +281,10 @@ static void CalculateDynamicMetadataParameters(
>   		double DISPCLK,
>   		double DCFClkDeepSleep,
>   		double PixelClock,
> -		long HTotal,
> -		long VBlank,
> -		long DynamicMetadataTransmittedBytes,
> -		long DynamicMetadataLinesBeforeActiveRequired,
> +		unsigned int HTotal,
> +		unsigned int VBlank,
> +		unsigned int DynamicMetadataTransmittedBytes,
> +		int DynamicMetadataLinesBeforeActiveRequired,
>   		int InterlaceEnable,
>   		bool ProgressiveToInterlaceUnitInOPP,
>   		double *Tsetup,
> @@ -3265,8 +3265,8 @@ static double CalculateWriteBackDelay(
>   
>   
>   static void CalculateDynamicMetadataParameters(int MaxInterDCNTileRepeaters, double DPPCLK, double DISPCLK,
> -		double DCFClkDeepSleep, double PixelClock, long HTotal, long VBlank, long DynamicMetadataTransmittedBytes,
> -		long DynamicMetadataLinesBeforeActiveRequired, int InterlaceEnable, bool ProgressiveToInterlaceUnitInOPP,
> +		double DCFClkDeepSleep, double PixelClock, unsigned int HTotal, unsigned int VBlank, unsigned int DynamicMetadataTransmittedBytes,
> +		int DynamicMetadataLinesBeforeActiveRequired, int InterlaceEnable, bool ProgressiveToInterlaceUnitInOPP,
>   		double *Tsetup, double *Tdmbf, double *Tdmec, double *Tdmsks)
>   {
>   	double TotalRepeaterDelayTime = 0;