From: Colin Ian King colin.king@canonical.com
The pointer disable_done is being initialized with a value that is never read and is being re-assigned a little later on. The assignment is redundant and hence can be removed.
Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King colin.king@canonical.com --- drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c index 75263d8cd0bd..9beeda04818b 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c @@ -296,7 +296,7 @@ komeda_crtc_atomic_disable(struct drm_crtc *crtc, struct komeda_crtc_state *old_st = to_kcrtc_st(old); struct komeda_pipeline *master = kcrtc->master; struct komeda_pipeline *slave = kcrtc->slave; - struct completion *disable_done = &crtc->state->commit->flip_done; + struct completion *disable_done; bool needs_phase2 = false;
DRM_DEBUG_ATOMIC("CRTC%d_DISABLE: active_pipes: 0x%x, affected: 0x%x\n",
On Fri, Oct 04, 2019 at 05:21:56PM +0100, Colin King wrote:
From: Colin Ian King colin.king@canonical.com
The pointer disable_done is being initialized with a value that is never read and is being re-assigned a little later on. The assignment is redundant and hence can be removed.
Not really true, isn't it? The re-assignment is done under the condition that crtc->state->active is true. disable_done will be used regardless after the if block, so we can't skip this initialisation.
Not sure why Coverity flags this, but I would NAK this patch.
Best regards, Liviu
Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King colin.king@canonical.com
drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c index 75263d8cd0bd..9beeda04818b 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c @@ -296,7 +296,7 @@ komeda_crtc_atomic_disable(struct drm_crtc *crtc, struct komeda_crtc_state *old_st = to_kcrtc_st(old); struct komeda_pipeline *master = kcrtc->master; struct komeda_pipeline *slave = kcrtc->slave;
- struct completion *disable_done = &crtc->state->commit->flip_done;
struct completion *disable_done; bool needs_phase2 = false;
DRM_DEBUG_ATOMIC("CRTC%d_DISABLE: active_pipes: 0x%x, affected: 0x%x\n",
-- 2.20.1
On 04/10/2019 20:27, Liviu Dudau wrote:
On Fri, Oct 04, 2019 at 05:21:56PM +0100, Colin King wrote:
From: Colin Ian King colin.king@canonical.com
The pointer disable_done is being initialized with a value that is never read and is being re-assigned a little later on. The assignment is redundant and hence can be removed.
Not really true, isn't it? The re-assignment is done under the condition that crtc->state->active is true. disable_done will be used regardless after the if block, so we can't skip this initialisation.
Not sure why Coverity flags this, but I would NAK this patch.
I'm patching against the driver from linux-next so I believe this is OK for that. I believe your statement is true against linux which does not have commit:
d6cb013579e743bc7bc5590ca35a1943f2b8f3c8 Author: Lowry Li (Arm Technology China) Lowry.Li@arm.com Date: Fri Sep 6 07:18:06 2019 +0000
Colin.
Best regards, Liviu
Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King colin.king@canonical.com
drivers/gpu/drm/arm/display/komeda/komeda_crtc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c index 75263d8cd0bd..9beeda04818b 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c @@ -296,7 +296,7 @@ komeda_crtc_atomic_disable(struct drm_crtc *crtc, struct komeda_crtc_state *old_st = to_kcrtc_st(old); struct komeda_pipeline *master = kcrtc->master; struct komeda_pipeline *slave = kcrtc->slave;
- struct completion *disable_done = &crtc->state->commit->flip_done;
struct completion *disable_done; bool needs_phase2 = false;
DRM_DEBUG_ATOMIC("CRTC%d_DISABLE: active_pipes: 0x%x, affected: 0x%x\n",
-- 2.20.1
On Fri, Oct 04, 2019 at 10:53:44PM +0100, Colin Ian King wrote:
On 04/10/2019 20:27, Liviu Dudau wrote:
On Fri, Oct 04, 2019 at 05:21:56PM +0100, Colin King wrote:
From: Colin Ian King colin.king@canonical.com
The pointer disable_done is being initialized with a value that is never read and is being re-assigned a little later on. The assignment is redundant and hence can be removed.
Not really true, isn't it? The re-assignment is done under the condition that crtc->state->active is true. disable_done will be used regardless after the if block, so we can't skip this initialisation.
Not sure why Coverity flags this, but I would NAK this patch.
I'm patching against the driver from linux-next so I believe this is OK for that. I believe your statement is true against linux which does not have commit:
d6cb013579e743bc7bc5590ca35a1943f2b8f3c8 Author: Lowry Li (Arm Technology China) Lowry.Li@arm.com Date: Fri Sep 6 07:18:06 2019 +0000
It really does help reviewing patches when this is mentioned in the commit message.
There is some debate about whether this should be mentioned as a Fixes since it doesn't fix a bug. I initialy felt it shouldn't be, but now I think enough people think it should be listed as Fixes that I must be wrong. Either way, it's very useful information.
The other thing is that soon get_maintainer.pl will start CC'ing people from the Fixes tag and right now Lowry Li is not CC'd so that's unfortunate.
regards, dan carpenter
On Mon, Oct 07, 2019 at 04:25:05PM +0300, Dan Carpenter wrote:
On Fri, Oct 04, 2019 at 10:53:44PM +0100, Colin Ian King wrote:
On 04/10/2019 20:27, Liviu Dudau wrote:
On Fri, Oct 04, 2019 at 05:21:56PM +0100, Colin King wrote:
From: Colin Ian King colin.king@canonical.com
The pointer disable_done is being initialized with a value that is never read and is being re-assigned a little later on. The assignment is redundant and hence can be removed.
Not really true, isn't it? The re-assignment is done under the condition that crtc->state->active is true. disable_done will be used regardless after the if block, so we can't skip this initialisation.
Not sure why Coverity flags this, but I would NAK this patch.
I'm patching against the driver from linux-next so I believe this is OK for that. I believe your statement is true against linux which does not have commit:
d6cb013579e743bc7bc5590ca35a1943f2b8f3c8 Author: Lowry Li (Arm Technology China) Lowry.Li@arm.com Date: Fri Sep 6 07:18:06 2019 +0000
It really does help reviewing patches when this is mentioned in the commit message.
There is some debate about whether this should be mentioned as a Fixes since it doesn't fix a bug. I initialy felt it shouldn't be, but now I think enough people think it should be listed as Fixes that I must be wrong. Either way, it's very useful information.
The other thing is that soon get_maintainer.pl will start CC'ing people from the Fixes tag and right now Lowry Li is not CC'd so that's unfortunate.
regards, dan carpenter
Hi Liviu:
Colin's code is right.
Following code I copied from linux-next, and I checked drm-misc, the code are same.
struct komeda_pipeline *slave = kcrtc->slave; //---- First initialization. struct completion *disable_done = &crtc->state->commit->flip_done; bool needs_phase2 = false;
DRM_DEBUG_ATOMIC("CRTC%d_DISABLE: active_pipes: 0x%x, affected: 0x%x\n", drm_crtc_index(crtc), old_st->active_pipes, old_st->affected_pipes);
if (slave && has_bit(slave->id, old_st->active_pipes)) komeda_pipeline_disable(slave, old->state);
if (has_bit(master->id, old_st->active_pipes)) needs_phase2 = komeda_pipeline_disable(master, old->state);
//---- Secondary initialization. disable_done = (needs_phase2 || crtc->state->active) ? NULL : &crtc->state->commit->flip_done;
//--- First using is here. /* wait phase 1 disable done */ komeda_crtc_flush_and_wait_for_flip_done(kcrtc, disable_done);
So the first initialization with the delcaration is unnecessary.
And I also checked our internal testing branch which actually doesn't have the first initialization. seems somethings wrong when lowry submit this to upstream.
Hi Colin:
Thanks for the fix. I'll push it to drm-misc-fixes
Reviewed-by: James Qian Wang (Arm Technology China) james.qian.wang@arm.com
Best Regards James
dri-devel@lists.freedesktop.org
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Colin Ian King -
Colin King
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Dan Carpenter -
james qian wang (Arm Technology China) -
Liviu Dudau