Commit 308eeb8c authored by Marek Vasut's avatar Marek Vasut Committed by Tomi Valkeinen
Browse files

drm/rcar-du: dsi: Handle both DRM_MODE_FLAG_N.SYNC and !DRM_MODE_FLAG_P.SYNC 



Since commit 94fe479f ("drm/rcar-du: dsi: Clean up handling of DRM mode flags")
the driver does not set TXVMVPRMSET0R_VSPOL_LOW and TXVMVPRMSET0R_HSPOL_LOW
for modes which set neither DRM_MODE_FLAG_[PN].SYNC. The previous behavior
was to assume that neither flag means DRM_MODE_FLAG_N.SYNC . Restore the
previous behavior for maximum compatibility.

The change of behavior is visible below, consider Vertical mode->flags
for simplicity sake, although the same applies to Horizontal ones:

Before 94fe479f ("drm/rcar-du: dsi: Clean up handling of DRM mode flags") :

- DRM_MODE_FLAG_PVSYNC => vprmset0r |= 0
- DRM_MODE_FLAG_NVSYNC => vprmset0r |= TXVMVPRMSET0R_VSPOL_LOW
- Neither DRM_MODE_FLAG_[PN]VSYNC => vprmset0r |= TXVMVPRMSET0R_VSPOL_LOW

After 94fe479f ("drm/rcar-du: dsi: Clean up handling of DRM mode flags") :

- DRM_MODE_FLAG_PVSYNC => vprmset0r |= 0
- DRM_MODE_FLAG_NVSYNC => vprmset0r |= TXVMVPRMSET0R_VSPOL_LOW
- Neither DRM_MODE_FLAG_[PN]VSYNC => vprmset0r |= 0 <---------- This broke

The "Neither" case behavior is different, because DRM_MODE_FLAG_N[HV]SYNC is
really not equivalent !DRM_MODE_FLAG_P[HV]SYNC .

Fixes: 94fe479f ("drm/rcar-du: dsi: Clean up handling of DRM mode flags")
Signed-off-by: default avatarMarek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://patch.msgid.link/20251202181146.138365-1-marek.vasut+renesas@mailbox.org


Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ideasonboard.com>
parent 4cbae374

drivers/gpu/drm/renesas/rcar-du/rcar_mipi_dsi.c

+2 −2
Original line number Diff line number Diff line
@@ -492,9 +492,9 @@ static void rcar_mipi_dsi_set_display_timing(struct rcar_mipi_dsi *dsi, 


	/* Configuration for Video Parameters, input is always RGB888 */

	vprmset0r = TXVMVPRMSET0R_BPP_24;

	if (mode->flags & DRM_MODE_FLAG_NVSYNC)

	if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))

		vprmset0r |= TXVMVPRMSET0R_VSPOL_LOW;

	if (mode->flags & DRM_MODE_FLAG_NHSYNC)

	if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))

		vprmset0r |= TXVMVPRMSET0R_HSPOL_LOW;



	vprmset1r = TXVMVPRMSET1R_VACTIVE(mode->vdisplay)