* [PATCH v2] drm/panel-edp: Add Sharp LQ120P1JX51 (Surface Pro 12in 1st Ed.) [not found] <20260731115127.15140-1-info@humanlearning.ch> @ 2026-08-02 13:50 ` François Roux 2026-08-03 20:02 ` Doug Anderson 0 siblings, 1 reply; 2+ messages in thread From: François Roux @ 2026-08-02 13:50 UTC (permalink / raw) To: Douglas Anderson, Neil Armstrong Cc: Jessica Zhang, Maxime Ripard, Thomas Zimmermann, dri-devel, linux-kernel, François Roux The internal eDP panel of the Microsoft Surface Pro 12in 1st Edition (Snapdragon X Plus, X1P42100) is not in edp_panels[], so every boot produces the deliberate WARN_ON splat in panel_edp_probe() and the panel falls back to conservative timings: WARNING: drivers/gpu/drm/panel/panel-edp.c:814 panel_edp_probe+0x53c/0x56c panel-simple-dp-aux aux-aea0000.displayport-controller: Unknown panel SHP 0x15a7, using conservative timings EDID, read over the panel's DP AUX DDC bus: 00 ff ff ff ff ff ff 00 4d 10 a7 15 a0 00 00 1f 31 22 01 04 a5 19 11 78 07 ee 91 a3 54 4c 99 26 0f 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 62 53 94 a0 80 b8 2e 50 18 10 3a 00 fe a9 00 00 00 18 13 7d 94 a0 80 b8 2e 50 18 10 3a 00 fe a9 00 00 00 18 00 00 00 fd 00 18 5a 88 88 21 01 00 00 00 00 00 00 00 00 00 00 fc 00 4c 51 31 32 30 50 31 4a 58 35 31 0a 20 00 69 Manufacturer: SHP Model: 0x15a7 Made in: week 49 of 2024 Display Product Name: 'LQ120P1JX51' DTD 1: 2196x1464 60.001799 Hz 3:2 (254 mm x 169 mm) DTD 2: 2196x1464 90.002698 Hz 3:2 (254 mm x 169 mm) Timings are deliberately cautious rather than datasheet-derived. The conservative fallback sets unprepare=2000 and enable=200; unprepare=2000 is a safety margin for unknown panels only and is the single occurrence of that value in the file -- no real panel entry uses it. delay_200_500_e200 keeps the same generous 200 ms enable delay while using the 500 ms unprepare shared by every actual panel in the table. A shorter enable delay may well be fine, but has not been validated here. Signed-off-by: François Roux <info@humanlearning.ch> --- Changes in v2: - Read the EDID over the panel's DP AUX DDC bus and included it in the commit message, as requested. My v1 claim that the EDID was not obtainable was wrong: the connector does not export it (/sys/class/drm/card0-eDP-1/edid is 0 bytes) and CONFIG_DRM_DP_AUX_CHARDEV no longer exists, but the AUX bus is registered as an i2c adapter, so a plain DDC read works: i2ctransfer -y <bus> w1@0x50 0x00 r128 (i2cdump in byte mode does not: it drops a header byte and yields a block with a bad checksum.) - The EDID carries a Display Product Name, so the entry is now "LQ120P1JX51" instead of "Unknown". - Timings unchanged (delay_200_500_e200). - Now sent under my real name, as you asked. v1 went out as "franzelverbier"; same person, same address. drivers/gpu/drm/panel/panel-edp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c index 13ce277d7..4defef820 100644 --- a/drivers/gpu/drm/panel/panel-edp.c +++ b/drivers/gpu/drm/panel/panel-edp.c @@ -2145,6 +2145,7 @@ static const struct edp_panel_entry edp_panels[] = { EDP_PANEL_ENTRY('S', 'H', 'P', 0x154c, &delay_200_500_p2e100, "LQ116M1JW10"), EDP_PANEL_ENTRY('S', 'H', 'P', 0x158f, &delay_200_500_p2e100, "LQ134Z1"), EDP_PANEL_ENTRY('S', 'H', 'P', 0x1593, &delay_200_500_p2e100, "LQ134N1"), + EDP_PANEL_ENTRY('S', 'H', 'P', 0x15a7, &delay_200_500_e200, "LQ120P1JX51"), EDP_PANEL_ENTRY('S', 'T', 'A', 0x0004, &delay_200_500_e200, "116KHD024006"), EDP_PANEL_ENTRY('S', 'T', 'A', 0x0009, &delay_200_500_e250, "116QHD024002"), ^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] drm/panel-edp: Add Sharp LQ120P1JX51 (Surface Pro 12in 1st Ed.) 2026-08-02 13:50 ` [PATCH v2] drm/panel-edp: Add Sharp LQ120P1JX51 (Surface Pro 12in 1st Ed.) François Roux @ 2026-08-03 20:02 ` Doug Anderson 0 siblings, 0 replies; 2+ messages in thread From: Doug Anderson @ 2026-08-03 20:02 UTC (permalink / raw) To: François Roux Cc: Neil Armstrong, Jessica Zhang, Maxime Ripard, Thomas Zimmermann, dri-devel, linux-kernel Hi, On Sun, Aug 2, 2026 at 6:51 AM François Roux <info@humanlearning.ch> wrote: > > The internal eDP panel of the Microsoft Surface Pro 12in 1st Edition > (Snapdragon X Plus, X1P42100) is not in edp_panels[], so every boot > produces the deliberate WARN_ON splat in panel_edp_probe() and the panel > falls back to conservative timings: > > WARNING: drivers/gpu/drm/panel/panel-edp.c:814 panel_edp_probe+0x53c/0x56c > panel-simple-dp-aux aux-aea0000.displayport-controller: > Unknown panel SHP 0x15a7, using conservative timings > > EDID, read over the panel's DP AUX DDC bus: > > 00 ff ff ff ff ff ff 00 4d 10 a7 15 a0 00 00 1f > 31 22 01 04 a5 19 11 78 07 ee 91 a3 54 4c 99 26 > 0f 50 54 00 00 00 01 01 01 01 01 01 01 01 01 01 > 01 01 01 01 01 01 62 53 94 a0 80 b8 2e 50 18 10 > 3a 00 fe a9 00 00 00 18 13 7d 94 a0 80 b8 2e 50 > 18 10 3a 00 fe a9 00 00 00 18 00 00 00 fd 00 18 > 5a 88 88 21 01 00 00 00 00 00 00 00 00 00 00 fc > 00 4c 51 31 32 30 50 31 4a 58 35 31 0a 20 00 69 > > Manufacturer: SHP > Model: 0x15a7 > Made in: week 49 of 2024 > Display Product Name: 'LQ120P1JX51' > DTD 1: 2196x1464 60.001799 Hz 3:2 (254 mm x 169 mm) > DTD 2: 2196x1464 90.002698 Hz 3:2 (254 mm x 169 mm) > > Timings are deliberately cautious rather than datasheet-derived. The > conservative fallback sets unprepare=2000 and enable=200; unprepare=2000 > is a safety margin for unknown panels only and is the single occurrence > of that value in the file -- no real panel entry uses it. > delay_200_500_e200 keeps the same generous 200 ms enable delay while > using the 500 ms unprepare shared by every actual panel in the table. A > shorter enable delay may well be fine, but has not been validated here. > > Signed-off-by: François Roux <info@humanlearning.ch> > --- > Changes in v2: > - Read the EDID over the panel's DP AUX DDC bus and included it in the > commit message, as requested. My v1 claim that the EDID was not > obtainable was wrong: the connector does not export it > (/sys/class/drm/card0-eDP-1/edid is 0 bytes) and > CONFIG_DRM_DP_AUX_CHARDEV no longer exists, but the AUX bus is > registered as an i2c adapter, so a plain DDC read works: > i2ctransfer -y <bus> w1@0x50 0x00 r128 > (i2cdump in byte mode does not: it drops a header byte and yields a > block with a bad checksum.) > - The EDID carries a Display Product Name, so the entry is now > "LQ120P1JX51" instead of "Unknown". > - Timings unchanged (delay_200_500_e200). > - Now sent under my real name, as you asked. v1 went out as > "franzelverbier"; same person, same address. > > drivers/gpu/drm/panel/panel-edp.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c > index 13ce277d7..4defef820 100644 > --- a/drivers/gpu/drm/panel/panel-edp.c > +++ b/drivers/gpu/drm/panel/panel-edp.c > @@ -2145,6 +2145,7 @@ static const struct edp_panel_entry edp_panels[] = { > EDP_PANEL_ENTRY('S', 'H', 'P', 0x154c, &delay_200_500_p2e100, "LQ116M1JW10"), > EDP_PANEL_ENTRY('S', 'H', 'P', 0x158f, &delay_200_500_p2e100, "LQ134Z1"), > EDP_PANEL_ENTRY('S', 'H', 'P', 0x1593, &delay_200_500_p2e100, "LQ134N1"), > + EDP_PANEL_ENTRY('S', 'H', 'P', 0x15a7, &delay_200_500_e200, "LQ120P1JX51"), Reviewed-by: Douglas Anderson <dianders@chromium.org> Pushed to drm-misc-next: [1/1] drm/panel-edp: Add Sharp LQ120P1JX51 (Surface Pro 12in 1st Ed.) commit: 6ed8d820cea9cae226f500d3af86e156eede27f6 ^ permalink raw reply [flat|nested] 2+ messages in thread
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2026-08-02 13:50 ` [PATCH v2] drm/panel-edp: Add Sharp LQ120P1JX51 (Surface Pro 12in 1st Ed.) François Roux
2026-08-03 20:02 ` Doug Anderson
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