diff --git a/drivers/gpu/drm/nouveau/nouveau_bios.c b/drivers/gpu/drm/nouveau/nouveau_bios.c index 075eb894648f..ad6c2d4520ae 100644 --- a/drivers/gpu/drm/nouveau/nouveau_bios.c +++ b/drivers/gpu/drm/nouveau/nouveau_bios.c @@ -3659,6 +3659,21 @@ int nouveau_bios_parse_lvds_table(struct drm_device *dev, int pxclk, bool *dl, b break; } + /* Dell Latitude D620 reports a too-high value for the dual-link + * transition freq, causing us to program the panel incorrectly. + * + * It doesn't appear the VBIOS actually uses its transition freq + * (90000kHz), instead it uses the "Number of LVDS channels" field + * out of the panel ID structure (http://www.spwg.org/). + * + * For the moment, a quirk will do :) + */ + if ((dev->pdev->device == 0x01d7) && + (dev->pdev->subsystem_vendor == 0x1028) && + (dev->pdev->subsystem_device == 0x01c2)) { + bios->fp.duallink_transition_clk = 80000; + } + /* set dual_link flag for EDID case */ if (pxclk && (chip_version < 0x25 || chip_version > 0x28)) bios->fp.dual_link = (pxclk >= bios->fp.duallink_transition_clk);