[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]

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.

Harry

>  	uint32_t read_dpcd_retry_cnt = 3;
>  	int i;
>  	struct dp_sink_hw_fw_revision dp_hw_fw_revision;
> 

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