Messages in this thread | | | Subject | Re: [v10,2/3] drm/mediatek: implement the DSI HS packets aligned | From | AngeloGioacchino Del Regno <> | Date | Wed, 19 Jan 2022 09:43:10 +0100 |
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Il 19/01/22 09:35, Andrzej Hajda ha scritto: > > On 19.01.2022 03:25, Rex-BC Chen wrote: >> Some DSI RX devices (for example, anx7625) require last alignment of >> packets on all lanes after each row of data is sent. >> Otherwise, there will be some issues of shift or scroll for screen. >> >> Take horizontal_sync_active_byte for a example, >> we roundup the HSA packet data to lane number, and the subtraction of 2 >> is the packet data value added by the roundup operation, making the >> long packets are integer multiples of lane number. >> This value (2) varies with the lane number, and that is the reason we >> do this operation when the lane number is 4. >> >> In the previous operation of function "mtk_dsi_config_vdo_timing", >> the length of HSA and HFP data packets has been adjusted to an >> integration multiple of lane number. >> Since the number of RGB data packets cannot be guaranteed to be an >> integer multiple of lane number, we modify the data packet length of >> HBP so that the number of HBP + RGB is equal to the lane number. >> So after sending a line of data (HSA + HBP + RGB + HFP), the data >> lanes are aligned. >> >> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com> >> Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com> >> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com> > > Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> > Regards > > Andrzej > >> --- >> drivers/gpu/drm/mediatek/mtk_dsi.c | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c >> index 5d90d2eb0019..e91b3fff4342 100644 >> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c >> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c >> @@ -500,6 +500,18 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi) >> DRM_WARN("HFP + HBP less than d-phy, FPS will under 60Hz\n"); >> } >> + if ((dsi->mode_flags & MIPI_DSI_HS_PKT_END_ALIGNED) && >> + (dsi->lanes == 4)) { >> + horizontal_sync_active_byte = >> + roundup(horizontal_sync_active_byte, dsi->lanes) - 2; >> + horizontal_frontporch_byte = >> + roundup(horizontal_frontporch_byte, dsi->lanes) - 2; >> + horizontal_backporch_byte = >> + roundup(horizontal_backporch_byte, dsi->lanes) - 2; >> + horizontal_backporch_byte -= >> + (vm->hactive * dsi_tmp_buf_bpp + 2) % dsi->lanes; >> + } >> + >> writel(horizontal_sync_active_byte, dsi->regs + DSI_HSA_WC); >> writel(horizontal_backporch_byte, dsi->regs + DSI_HBP_WC); >> writel(horizontal_frontporch_byte, dsi->regs + DSI_HFP_WC);
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