Messages in this thread Patch in this message | | | From | CK Hu (胡俊光) <> | Subject | Re: [PATCH v6 9/9] drm/mediatek: dsi: Use mipi_dsi_pixel_format_to_bpp() helper function | Date | Thu, 15 Feb 2024 09:28:16 +0000 |
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Hi, Angelo:
On Thu, 2024-02-15 at 09:53 +0100, 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.
Reviewed-by: CK Hu <ck.hu@mediatek.com>
> > Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com> > 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(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c > b/drivers/gpu/drm/mediatek/mtk_dsi.c > index b644505de98a..9501f4019199 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;
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