[PATCH][next] drm/amd/display: remove redundant assignment to status

[PATCH][next] drm/amd/display: remove redundant assignment to status

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

The variable status is initialized with a value that is never read
and status is reassigned several statements later. This initialization
is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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 65d6caedbd82..cf6166a1be53 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
@@ -2367,7 +2367,7 @@ static bool retrieve_link_cap(struct dc_link *link)
 	union down_stream_port_count down_strm_port_count;
 	union edp_configuration_cap edp_config_cap;
 	union dp_downstream_port_present ds_port = { 0 };
-	enum dc_status status = DC_ERROR_UNEXPECTED;
+	enum dc_status status;
 	uint32_t read_dpcd_retry_cnt = 3;
 	int i;
 	struct dp_sink_hw_fw_revision dp_hw_fw_revision;
-- 
2.20.1

Re: [PATCH][next] drm/amd/display: remove redundant assignment to status

[Harry Wentland]

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Re: [PATCH][next] drm/amd/display: remove redundant assignment to status

[Dan Carpenter]

On Fri, May 31, 2019 at 08:19:03PM +0000, Harry Wentland wrote:
> On 2019-05-30 12:12 p.m., Colin King wrote:
> > From: Colin Ian King <colin.king@canonical.com>
> > 
> > The variable status is initialized with a value that is never read
> > and status is reassigned several statements later. This initialization
> > is redundant and can be removed.
> > 
> > Addresses-Coverity: ("Unused value")
> > Signed-off-by: Colin Ian King <colin.king@canonical.com>
> > ---
> >  drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > 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 65d6caedbd82..cf6166a1be53 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
> > @@ -2367,7 +2367,7 @@ static bool retrieve_link_cap(struct dc_link *link)
> >  	union down_stream_port_count down_strm_port_count;
> >  	union edp_configuration_cap edp_config_cap;
> >  	union dp_downstream_port_present ds_port = { 0 };
> > -	enum dc_status status = DC_ERROR_UNEXPECTED;
> > +	enum dc_status status;
> 
> Not sure this improves the situation.
> 
> I'd prefer to have a default here in case someone changes the code below
> and forgets to set the status.

The dead code confuses human readers, because people naturally assume it
is not dead.

GCC has a feature to warn about uninitialized variables and we're
randomly initializing status to a bogus value to disable static
analysis...

regards,
dan carpenter

[PATCH][next] drm/amd/display: remove redundant variable status

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

Variable status is redundant, it is being initialized with a value
that is over-written later and this is being returned immediately
after the assignment.  Clean up the code by removing status and
just returning the value returned from the call to function
dc->hwss.dmdata_status_done.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
index 371d49e9b745..88a84bfaea6f 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -565,7 +565,6 @@ bool dc_stream_get_scanoutpos(const struct dc_stream_state *stream,
 
 bool dc_stream_dmdata_status_done(struct dc *dc, struct dc_stream_state *stream)
 {
-	bool status = true;
 	struct pipe_ctx *pipe = NULL;
 	int i;
 
@@ -581,8 +580,7 @@ bool dc_stream_dmdata_status_done(struct dc *dc, struct dc_stream_state *stream)
 	if (i = MAX_PIPES)
 		return true;
 
-	status = dc->hwss.dmdata_status_done(pipe);
-	return status;
+	return dc->hwss.dmdata_status_done(pipe);
 }
 
 bool dc_stream_set_dynamic_metadata(struct dc *dc,
-- 
2.20.1

Re: [PATCH][next] drm/amd/display: remove redundant variable status

[Alex Deucher]

On Fri, Nov 8, 2019 at 11:29 AM Colin King <colin.king@canonical.com> wrote:
>
> From: Colin Ian King <colin.king@canonical.com>
>
> Variable status is redundant, it is being initialized with a value
> that is over-written later and this is being returned immediately
> after the assignment.  Clean up the code by removing status and
> just returning the value returned from the call to function
> dc->hwss.dmdata_status_done.
>
> Addresses-Coverity: ("Unused value")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Applied.  thanks!

Alex

> ---
>  drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
> index 371d49e9b745..88a84bfaea6f 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
> @@ -565,7 +565,6 @@ bool dc_stream_get_scanoutpos(const struct dc_stream_state *stream,
>
>  bool dc_stream_dmdata_status_done(struct dc *dc, struct dc_stream_state *stream)
>  {
> -       bool status = true;
>         struct pipe_ctx *pipe = NULL;
>         int i;
>
> @@ -581,8 +580,7 @@ bool dc_stream_dmdata_status_done(struct dc *dc, struct dc_stream_state *stream)
>         if (i = MAX_PIPES)
>                 return true;
>
> -       status = dc->hwss.dmdata_status_done(pipe);
> -       return status;
> +       return dc->hwss.dmdata_status_done(pipe);
>  }
>
>  bool dc_stream_set_dynamic_metadata(struct dc *dc,
> --
> 2.20.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

[PATCH][next] drm/amd/display: remove redundant assignment to variable ret

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

The variable ret is being initialized with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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 d5b306384d79..9ef9e50a34fa 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
@@ -4231,7 +4231,7 @@ void dpcd_set_source_specific_data(struct dc_link *link)
 {
 	const uint32_t post_oui_delay = 30; // 30ms
 	uint8_t dspc = 0;
-	enum dc_status ret = DC_ERROR_UNEXPECTED;
+	enum dc_status ret;
 
 	ret = core_link_read_dpcd(link, DP_DOWN_STREAM_PORT_COUNT, &dspc,
 				  sizeof(dspc));
-- 
2.25.1

Re: [PATCH][next] drm/amd/display: remove redundant assignment to variable ret

[Alex Deucher]

On Thu, Apr 23, 2020 at 10:18 AM Colin King <colin.king@canonical.com> wrote:
>
> From: Colin Ian King <colin.king@canonical.com>
>
> The variable ret is being initialized with a value that is never read
> and it is being updated later with a new value. The initialization is
> redundant and can be removed.
>
> Addresses-Coverity: ("Unused value")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Applied.  Thanks!

Alex

> ---
>  drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> 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 d5b306384d79..9ef9e50a34fa 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
> @@ -4231,7 +4231,7 @@ void dpcd_set_source_specific_data(struct dc_link *link)
>  {
>         const uint32_t post_oui_delay = 30; // 30ms
>         uint8_t dspc = 0;
> -       enum dc_status ret = DC_ERROR_UNEXPECTED;
> +       enum dc_status ret;
>
>         ret = core_link_read_dpcd(link, DP_DOWN_STREAM_PORT_COUNT, &dspc,
>                                   sizeof(dspc));
> --
> 2.25.1
>
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