Hi,
On 14/08/2025 00:08, Marek Vasut wrote:
> Remove fixed PPI lane count setup. The R-Car DSI host is capable
> of operating in 1..4 DSI lane mode. Remove the hard-coded 4-lane
> configuration from PPI register settings and instead configure
> the PPI lane count according to lane count information already
> obtained by this driver instance.
>
> Configure TXSETR register to match PPI lane count. The R-Car V4H
> Reference Manual R19UH0186EJ0121 Rev.1.21 section 67.2.2.3 Tx Set
> Register (TXSETR), field LANECNT description indicates that the
> TXSETR register LANECNT bitfield lane count must be configured
> such, that it matches lane count configuration in PPISETR register
> DLEN bitfield. Make sure the LANECNT and DLEN bitfields are
> configured to match.
>
> Fixes: 155358310f01 ("drm: rcar-du: Add R-Car DSI driver")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
> ---
> Cc: David Airlie <airlied@xxxxxxxxx>
> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Cc: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> Cc: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Cc: Magnus Damm <magnus.damm@xxxxxxxxx>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: Simona Vetter <simona@xxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
> ---
> V2: - Split this out of a series, update commit message, combine from
> drm/rcar-du: dsi: Remove fixed PPI lane count setup
> drm/rcar-du: dsi: Configure TXSETR register to match PPI lane count
> - add Fixes tag, CC stable
> ---
> drivers/gpu/drm/renesas/rcar-du/rcar_mipi_dsi.c | 5 ++++-
> drivers/gpu/drm/renesas/rcar-du/rcar_mipi_dsi_regs.h | 8 ++++----
> 2 files changed, 8 insertions(+), 5 deletions(-)
Reviewed-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
Tomi
