From: Arnd Bergmann <arnd@arndb.de>
To: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>,
David Airlie <airlied@linux.ie>
Cc: Arnd Bergmann <arnd@arndb.de>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: [PATCH] [RESEND] drm/gma500: initialize gma_clock_t structures
Date: Tue, 16 Jan 2018 15:57:10 +0100 [thread overview]
Message-ID: <20180116145720.2348043-1-arnd@arndb.de> (raw)
The two functions pass a partially initialized structure back to the
caller after a memset() on the destination.
This is not entirely well-defined, most compilers are sensible enough
to either keep the zero-initialization for the uninitialized members,
but gcc-4.4 does not, and it warns about this:
drivers/gpu/drm/gma500/oaktrail_crtc.c: In function 'mrst_sdvo_find_best_pll':
drivers/gpu/drm/gma500/oaktrail_crtc.c:175: warning: 'clock.vco' may be used uninitialized in this function
drivers/gpu/drm/gma500/oaktrail_crtc.c:175: warning: 'clock.dot' may be used uninitialized in this function
drivers/gpu/drm/gma500/oaktrail_crtc.c:175: warning: 'clock.p2' may be used uninitialized in this function
drivers/gpu/drm/gma500/oaktrail_crtc.c:175: warning: 'clock.m2' may be used uninitialized in this function
drivers/gpu/drm/gma500/oaktrail_crtc.c:175: warning: 'clock.m1' may be used uninitialized in this function
drivers/gpu/drm/gma500/oaktrail_crtc.c: In function 'mrst_lvds_find_best_pll':
drivers/gpu/drm/gma500/oaktrail_crtc.c:208: warning: 'clock.p' may be used uninitialized in this function
drivers/gpu/drm/gma500/oaktrail_crtc.c:208: warning: 'clock.vco' may be used uninitialized in this function
drivers/gpu/drm/gma500/oaktrail_crtc.c:208: warning: 'clock.p2' may be used uninitialized in this function
drivers/gpu/drm/gma500/oaktrail_crtc.c:208: warning: 'clock.m2' may be used uninitialized in this function
drivers/gpu/drm/gma500/oaktrail_crtc.c:208: warning: 'clock.m1' may be used uninitialized in this function
drivers/gpu/drm/gma500/oaktrail_crtc.c:208: warning: 'clock.n' may be used uninitialized in this function
This adds an initialization at declaration time to avoid the warning
and make it well-defined on all compiler versions.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
Originally submitted on Sep 15, 2017, but got no reply. Resending unchanged.
---
drivers/gpu/drm/gma500/oaktrail_crtc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/gma500/oaktrail_crtc.c b/drivers/gpu/drm/gma500/oaktrail_crtc.c
index 0fff269d3fe6..b49fe79c3f44 100644
--- a/drivers/gpu/drm/gma500/oaktrail_crtc.c
+++ b/drivers/gpu/drm/gma500/oaktrail_crtc.c
@@ -134,7 +134,7 @@ static bool mrst_sdvo_find_best_pll(const struct gma_limit_t *limit,
struct drm_crtc *crtc, int target,
int refclk, struct gma_clock_t *best_clock)
{
- struct gma_clock_t clock;
+ struct gma_clock_t clock = {};
u32 target_vco, actual_freq;
s32 freq_error, min_error = 100000;
@@ -191,7 +191,7 @@ static bool mrst_lvds_find_best_pll(const struct gma_limit_t *limit,
struct drm_crtc *crtc, int target,
int refclk, struct gma_clock_t *best_clock)
{
- struct gma_clock_t clock;
+ struct gma_clock_t clock = {};
int err = target;
memset(best_clock, 0, sizeof(*best_clock));
--
2.9.0
next reply other threads:[~2018-01-16 14:57 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-16 14:57 Arnd Bergmann [this message]
2018-01-17 8:23 ` Patrik Jakobsson
2018-01-17 8:27 ` Daniel Vetter
2018-01-17 14:36 ` Arnd Bergmann
2018-01-17 14:55 ` Daniel Vetter
2018-01-17 19:44 ` Arnd Bergmann
2018-01-17 21:19 ` Daniel Vetter
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