diff options
| author | David Lechner <dlechner@baylibre.com> | 2026-02-28 22:30:30 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-19 16:08:15 +0100 |
| commit | fc7735caf016a38261f0edb3144baeba5d84f2e9 (patch) | |
| tree | 4a8abcab15564baaf0775405a04759e7488ae4b8 /drivers/gpu/drm | |
| parent | c34ebd7b24ea70be3c6fdb6936f79f593f37df60 (diff) | |
drm/sitronix/st7586: fix bad pixel data due to byte swap
[ Upstream commit 46d8a07b4ae262e2fec6ce2aa454e06243661265 ]
Correctly set dbi->write_memory_bpw for the ST7586 driver. This driver
is for a monochrome display that has an unusual data format, so the
default value set in mipi_dbi_spi_init() is not correct simply because
this controller is non-standard.
Previously, we were using dbi->swap_bytes to make the same sort of
workaround, but it was removed in the same commit that added
dbi->write_memory_bpw, so we need to use the latter now to have the
correct behavior.
This fixes every 3 columns of pixels being swapped on the display. There
are 3 pixels per byte, so the byte swap caused this effect.
Fixes: df3fb27a74a4 ("drm/mipi-dbi: Make bits per word configurable for pixel transfers")
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20260228-drm-mipi-dbi-fix-st7586-byte-swap-v1-1-e78f6c24cd28@baylibre.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/sitronix/st7586.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/drivers/gpu/drm/sitronix/st7586.c b/drivers/gpu/drm/sitronix/st7586.c index a29672d84ede..055383497aae 100644 --- a/drivers/gpu/drm/sitronix/st7586.c +++ b/drivers/gpu/drm/sitronix/st7586.c @@ -346,6 +346,12 @@ static int st7586_probe(struct spi_device *spi) if (ret) return ret; + /* + * Override value set by mipi_dbi_spi_init(). This driver is a bit + * non-standard, so best to set it explicitly here. + */ + dbi->write_memory_bpw = 8; + /* Cannot read from this controller via SPI */ dbi->read_commands = NULL; @@ -355,15 +361,6 @@ static int st7586_probe(struct spi_device *spi) if (ret) return ret; - /* - * we are using 8-bit data, so we are not actually swapping anything, - * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the - * right thing and not use 16-bit transfers (which results in swapped - * bytes on little-endian systems and causes out of order data to be - * sent to the display). - */ - dbi->swap_bytes = true; - drm_mode_config_reset(drm); ret = drm_dev_register(drm, 0); |