Re: [PATCH][next] drm/amd/display: fix for-loop with incorrectly sized loop counter

From: walter harms
Date: Fri Jan 17 2020 - 09:35:15 EST




Am 17.01.2020 14:33, schrieb Colin King:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> A for-loop is iterating from 0 up to 1000 however the loop variable count
> is a u8 and hence not large enough. Fix this by making count an int.
> Also remove the redundant initialization of count since this is never used
> and add { } on the loop statement make the loop block clearer.
>
> Addresses-Coverity: ("Operands don't affect result")
> Fixes: ed581a0ace44 ("drm/amd/display: wait for update when setting dpg test pattern")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> index 6ab298c65247..cbed738a4246 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> @@ -3680,7 +3680,7 @@ static void set_crtc_test_pattern(struct dc_link *link,
> struct pipe_ctx *odm_pipe;
> enum controller_dp_color_space controller_color_space;
> int opp_cnt = 1;
> - uint8_t count = 0;
> + int count;
>
> switch (test_pattern_color_space) {
> case DP_TEST_PATTERN_COLOR_SPACE_RGB:
> @@ -3725,11 +3725,12 @@ static void set_crtc_test_pattern(struct dc_link *link,
> width,
> height);
> /* wait for dpg to blank pixel data with test pattern */
> - for (count = 0; count < 1000; count++)
> + for (count = 0; count < 1000; count++) {
> if (opp->funcs->dpg_is_blanked(opp))
> break;
> else
> udelay(100);
> + }
> }
> }
> break;

Nitpick:
the else is useless you can remove it.

re,
wh