| Message ID | 20240206120748.136610-10-angelogioacchino.delregno@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | MediaTek DRM - DSI driver cleanups | expand |
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com> On 06/02/2024 13:07, AngeloGioacchino Del Regno wrote: > Instead of open coding, use the mipi_dsi_pixel_format_to_bpp() helper > function from drm_mipi_dsi.h in mtk_dsi_poweron() and for validation > in mtk_dsi_bridge_mode_valid(). > > Note that this function changes the behavior of this driver: previously, > in case of unknown formats, it would (wrongly) assume that it should > account for a 24-bits format - now it will return an error and refuse > to set clocks and/or enable the DSI. > > This is done because setting the wrong data rate will only produce a > garbage output that the display will misinterpret both because this > driver doesn't actually provide any extra-spec format support and/or > because the data rate (hence, the HS clock) will be wrong.
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index 545c5cc071d9..d844a0500e2b 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -598,19 +598,12 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi) if (++dsi->refcount != 1) return 0; - switch (dsi->format) { - case MIPI_DSI_FMT_RGB565: - bit_per_pixel = 16; - break; - case MIPI_DSI_FMT_RGB666_PACKED: - bit_per_pixel = 18; - break; - case MIPI_DSI_FMT_RGB666: - case MIPI_DSI_FMT_RGB888: - default: - bit_per_pixel = 24; - break; + ret = mipi_dsi_pixel_format_to_bpp(dsi->format); + if (ret < 0) { + dev_err(dev, "Unknown MIPI DSI format %d\n", dsi->format); + return ret; } + bit_per_pixel = ret; dsi->data_rate = DIV_ROUND_UP_ULL(dsi->vm.pixelclock * bit_per_pixel, dsi->lanes); @@ -793,12 +786,11 @@ mtk_dsi_bridge_mode_valid(struct drm_bridge *bridge, const struct drm_display_mode *mode) { struct mtk_dsi *dsi = bridge_to_dsi(bridge); - u32 bpp; + int bpp; - if (dsi->format == MIPI_DSI_FMT_RGB565) - bpp = 16; - else - bpp = 24; + bpp = mipi_dsi_pixel_format_to_bpp(dsi->format); + if (bpp < 0) + return MODE_ERROR; if (mode->clock * bpp / dsi->lanes > 1500000) return MODE_CLOCK_HIGH;
Instead of open coding, use the mipi_dsi_pixel_format_to_bpp() helper function from drm_mipi_dsi.h in mtk_dsi_poweron() and for validation in mtk_dsi_bridge_mode_valid(). Note that this function changes the behavior of this driver: previously, in case of unknown formats, it would (wrongly) assume that it should account for a 24-bits format - now it will return an error and refuse to set clocks and/or enable the DSI. This is done because setting the wrong data rate will only produce a garbage output that the display will misinterpret both because this driver doesn't actually provide any extra-spec format support and/or because the data rate (hence, the HS clock) will be wrong. Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> --- drivers/gpu/drm/mediatek/mtk_dsi.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-)