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

1 files changed, 12 insertions, 11 deletions

diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
index 4c37c4f6d26c..fc03046de134 100644
--- a/drivers/gpu/drm/panel/panel-edp.c
+++ b/drivers/gpu/drm/panel/panel-edp.c
@@ -1745,10 +1745,11 @@ static const struct panel_delay delay_200_500_e50 = {
 	.enable = 50,
 };
 
-#define EDP_PANEL_ENTRY(vend, product_id, _delay, _name) \
+#define EDP_PANEL_ENTRY(vend_chr_0, vend_chr_1, vend_chr_2, product_id, _delay, _name) \
 { \
 	.name = _name, \
-	.panel_id = drm_edid_encode_panel_id(vend, product_id), \
+	.panel_id = drm_edid_encode_panel_id(vend_chr_0, vend_chr_1, vend_chr_2, \
+					     product_id), \
 	.delay = _delay \
 }
 
@@ -1760,19 +1761,19 @@ static const struct panel_delay delay_200_500_e50 = {
  * Sort first by vendor, then by product ID.
  */
 static const struct edp_panel_entry edp_panels[] = {
-	EDP_PANEL_ENTRY("AUO", 0x405c, &auo_b116xak01.delay, "B116XAK01"),
-	EDP_PANEL_ENTRY("AUO", 0x615c, &delay_200_500_e50, "B116XAN06.1"),
+	EDP_PANEL_ENTRY('A', 'U', 'O', 0x405c, &auo_b116xak01.delay, "B116XAK01"),
+	EDP_PANEL_ENTRY('A', 'U', 'O', 0x615c, &delay_200_500_e50, "B116XAN06.1"),
 
-	EDP_PANEL_ENTRY("BOE", 0x0786, &delay_200_500_p2e80, "NV116WHM-T01"),
-	EDP_PANEL_ENTRY("BOE", 0x07d1, &boe_nv133fhm_n61.delay, "NV133FHM-N61"),
-	EDP_PANEL_ENTRY("BOE", 0x082d, &boe_nv133fhm_n61.delay, "NV133FHM-N62"),
-	EDP_PANEL_ENTRY("BOE", 0x098d, &boe_nv110wtm_n61.delay, "NV110WTM-N61"),
+	EDP_PANEL_ENTRY('B', 'O', 'E', 0x0786, &delay_200_500_p2e80, "NV116WHM-T01"),
+	EDP_PANEL_ENTRY('B', 'O', 'E', 0x07d1, &boe_nv133fhm_n61.delay, "NV133FHM-N61"),
+	EDP_PANEL_ENTRY('B', 'O', 'E', 0x082d, &boe_nv133fhm_n61.delay, "NV133FHM-N62"),
+	EDP_PANEL_ENTRY('B', 'O', 'E', 0x098d, &boe_nv110wtm_n61.delay, "NV110WTM-N61"),
 
-	EDP_PANEL_ENTRY("CMN", 0x114c, &innolux_n116bca_ea1.delay, "N116BCA-EA1"),
+	EDP_PANEL_ENTRY('C', 'M', 'N', 0x114c, &innolux_n116bca_ea1.delay, "N116BCA-EA1"),
 
-	EDP_PANEL_ENTRY("KDB", 0x0624, &kingdisplay_kd116n21_30nv_a010.delay, "116N21-30NV-A010"),
+	EDP_PANEL_ENTRY('K', 'D', 'B', 0x0624, &kingdisplay_kd116n21_30nv_a010.delay, "116N21-30NV-A010"),
 
-	EDP_PANEL_ENTRY("SHP", 0x154c, &delay_200_500_p2e100, "LQ116M1JW10"),
+	EDP_PANEL_ENTRY('S', 'H', 'P', 0x154c, &delay_200_500_p2e100, "LQ116M1JW10"),
 
 	{ /* sentinal */ }
 };