| Message ID | 20190103194845.GA26175@embeddedor (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/amd/display: Fix boolean expression in get_surf_rq_param | expand |
On 1/3/19 3:11 PM, Wentland, Harry wrote: > On 2019-01-03 2:48 p.m., Gustavo A. R. Silva wrote: >> Fix boolean expression by using logical AND operator '&&' >> instead of bitwise operator '&'. >> >> This issue was detected with the help of Coccinelle. >> >> Fixes: 6d04ee9dc101 ("drm/amd/display: Restructuring and cleaning up DML") >> Cc: stable@vger.kernel.org >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > > Reviewed-by: Harry Wentland <harry.wentland@amd.com> > > and applied. > Thanks, Harry. -- Gustavo
Hi Harry, I noticed this patch is already in mainline, but the stable tag was removed. What is the reason for that if this bug is present in stable? Thanks -- Gustavo On 1/3/19 3:11 PM, Wentland, Harry wrote: > On 2019-01-03 2:48 p.m., Gustavo A. R. Silva wrote: >> Fix boolean expression by using logical AND operator '&&' >> instead of bitwise operator '&'. >> >> This issue was detected with the help of Coccinelle. >> >> Fixes: 6d04ee9dc101 ("drm/amd/display: Restructuring and cleaning up DML") >> Cc: stable@vger.kernel.org >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > > Reviewed-by: Harry Wentland <harry.wentland@amd.com> > > and applied. > > Harry > >> --- >> drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c b/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c >> index c2037daa8e66..d341b69fdc1a 100644 >> --- a/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c >> +++ b/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c >> @@ -881,7 +881,7 @@ static void get_surf_rq_param( >> /* the dpte_group_bytes is reduced for the specific case of vertical >> * access of a tile surface that has dpte request of 8x1 ptes. >> */ >> - if (!surf_linear & (log2_dpte_req_height_ptes == 0) & surf_vert) /*reduced, in this case, will have page fault within a group */ >> + if (!surf_linear && (log2_dpte_req_height_ptes == 0) && surf_vert) /*reduced, in this case, will have page fault within a group */ >> rq_sizing_param->dpte_group_bytes = 512; >> else >> /*full size */ >>
On Thu, 2019-03-21 at 22:10 -0500, Gustavo A. R. Silva wrote: > Hi Harry, > > I noticed this patch is already in mainline, but the stable tag > was removed. What is the reason for that if this bug is present > in stable? It's not a bug, it's just a style issue and the && use in some compilers it may be slower. bool when set is 1.
On 3/21/19 10:14 PM, Joe Perches wrote: > On Thu, 2019-03-21 at 22:10 -0500, Gustavo A. R. Silva wrote: >> Hi Harry, >> >> I noticed this patch is already in mainline, but the stable tag >> was removed. What is the reason for that if this bug is present >> in stable? > > It's not a bug, it's just a style issue and > the && use in some compilers it may be slower. > You're right. What might be a bug in some cases is the other way around. Thanks, Joe. -- Gustavo
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c b/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c index c2037daa8e66..d341b69fdc1a 100644 --- a/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c +++ b/drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c @@ -881,7 +881,7 @@ static void get_surf_rq_param( /* the dpte_group_bytes is reduced for the specific case of vertical * access of a tile surface that has dpte request of 8x1 ptes. */ - if (!surf_linear & (log2_dpte_req_height_ptes == 0) & surf_vert) /*reduced, in this case, will have page fault within a group */ + if (!surf_linear && (log2_dpte_req_height_ptes == 0) && surf_vert) /*reduced, in this case, will have page fault within a group */ rq_sizing_param->dpte_group_bytes = 512; else /*full size */
Fix boolean expression by using logical AND operator '&&' instead of bitwise operator '&'. This issue was detected with the help of Coccinelle. Fixes: 6d04ee9dc101 ("drm/amd/display: Restructuring and cleaning up DML") Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)