2019-05-30 16:13:55

by Colin King

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

From: Colin Ian King <[email protected]>

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 <[email protected]>
---
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

2019-05-31 20:20:28

by Harry Wentland

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

On 2019-05-30 12:12 p.m., Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> 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 <[email protected]>
> ---
> 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;
>

2019-06-06 10:32:44

by Dan Carpenter

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

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 <[email protected]>
> >
> > 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 <[email protected]>
> > ---
> > 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