Re: [PATCH][next] drm/mgag200: Fix uninitialized variable delta

From: Thomas Zimmermann
Date: Tue Aug 17 2021 - 14:22:35 EST


Hi

Am 17.08.21 um 18:32 schrieb Colin King:
From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The variable delta is not initialized and this will cause unexpected
behaviour with the comparison of tmpdelta < delta. Fix this by setting
it to 0xffffffff. This matches the behaviour as in the similar function
mgag200_pixpll_compute_g200se_04.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 2545ac960364 ("drm/mgag200: Abstract pixel PLL via struct mgag200_pll")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

But the commit message needs Fixes etc. I just sent out a patch for this issue myself. I'd like to merge both patches' tags and commit the result under your name. (You were first.) Is that ok for you?

Best regards
Thomas

---
drivers/gpu/drm/mgag200/mgag200_pll.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/mgag200/mgag200_pll.c b/drivers/gpu/drm/mgag200/mgag200_pll.c
index 7c903cf19c0d..18f1a6dd019a 100644
--- a/drivers/gpu/drm/mgag200/mgag200_pll.c
+++ b/drivers/gpu/drm/mgag200/mgag200_pll.c
@@ -125,6 +125,7 @@ static int mgag200_pixpll_compute_g200se_00(struct mgag200_pll *pixpll, long clo
m = n = p = s = 0;
permitteddelta = clock * 5 / 1000;
+ delta = 0xffffffff;
for (testp = 8; testp > 0; testp /= 2) {
if (clock * testp > vcomax)


--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

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