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| author |   Douglas Anderson <dianders@chromium.org> | 2021-09-24 07:53:21 -0700 |
|---|---|---|
| committer | Douglas Anderson <dianders@chromium.org> | 2021-09-24 14:56:36 -0700 |
| commit | 7d1be0a09fa62139f1a29ccbe6d46aa04616539b (patch) | |
| tree | 38f388418fdeececdafd8a2e6b855ae03a4bdb27 /include | |
| parent | drm/gma500: Fix wrong pointer passed to PTR_ERR() (diff) | |
| download | linux-dev-7d1be0a09fa62139f1a29ccbe6d46aa04616539b.tar.xz linux-dev-7d1be0a09fa62139f1a29ccbe6d46aa04616539b.zip | |
drm/edid: Fix EDID quirk compile error on older compilers
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.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69960#c18
[2] https://lore.kernel.org/r/874kaabdt5.fsf@intel.com/
[3] https://lore.kernel.org/r/20210909135838.v4.4.I6103ce2b16e5e5a842b14c7022a034712b434609@changeid/
Fixes: d9f91a10c3e8 ("drm/edid: Allow querying/working with the panel ID from the EDID")
Reported-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Reported-by: Srikanth Myakam <smyakam@microsoft.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924075317.1.I1e58d74d501613f1fe7585958f451160d11b8a98@changeid
Diffstat (limited to 'include')
| -rw-r--r-- | include/drm/drm_edid.h | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h index ccc80cb7f86a..4d17cd04fff7 100644 --- a/include/drm/drm_edid.h +++ b/include/drm/drm_edid.h @@ -510,21 +510,23 @@ static inline u8 drm_eld_get_conn_type(const uint8_t *eld) /** * drm_edid_encode_panel_id - Encode an ID for matching against drm_edid_get_panel_id() - * @vend: 3-character vendor string + * @vend_chr_0: First character of the vendor string. + * @vend_chr_2: Second character of the vendor string. + * @vend_chr_3: Third character of the vendor string. * @product_id: The 16-bit product ID. * * This is a macro so that it can be calculated at compile time and used * as an initializer. * * For instance: - * drm_edid_encode_panel_id("BOE", 0x2d08) => 0x09e52d08 + * drm_edid_encode_panel_id('B', 'O', 'E', 0x2d08) => 0x09e52d08 * * Return: a 32-bit ID per panel. */ -#define drm_edid_encode_panel_id(vend, product_id) \ - ((((u32)((vend)[0]) - '@') & 0x1f) << 26 | \ - (((u32)((vend)[1]) - '@') & 0x1f) << 21 | \ - (((u32)((vend)[2]) - '@') & 0x1f) << 16 | \ +#define drm_edid_encode_panel_id(vend_chr_0, vend_chr_1, vend_chr_2, product_id) \ + ((((u32)(vend_chr_0) - '@') & 0x1f) << 26 | \ + (((u32)(vend_chr_1) - '@') & 0x1f) << 21 | \ + (((u32)(vend_chr_2) - '@') & 0x1f) << 16 | \ ((product_id) & 0xffff)) /** |