Re: [PATCH] drm/edid: Fix EDID quirk compile error on older compilers

From: Randy Dunlap
Date: Fri Sep 24 2021 - 11:24:14 EST

On 9/24/21 7:53 AM, Douglas Anderson wrote:
Apparently some compilers [1] cannot handle doing math on dereferenced
string constants at compile time. This has led to reports [2] of
compile errors like:

In file included from drivers/gpu/drm/drm_edid.c:42:0:
./include/drm/drm_edid.h:525:2: error: initializer element is not constant
((((u32)((vend)[0]) - '@') & 0x1f) << 26 | \

Go back to the syntax I used in v4 of the patch series [3] that added
this code instead of what landed (v5). This syntax is slightly uglier
but should be much more compatible with varied compilers.


Fixes: d9f91a10c3e8 ("drm/edid: Allow querying/working with the panel ID from the EDID")
Reported-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
Reported-by: Srikanth Myakam <smyakam@xxxxxxxxxxxxx>
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

drivers/gpu/drm/drm_edid.c | 121 +++++++++++++++---------------
drivers/gpu/drm/panel/panel-edp.c | 23 +++---
include/drm/drm_edid.h | 14 ++--
3 files changed, 81 insertions(+), 77 deletions(-)

Works for me. Thanks.

Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> # build-tested