Commit 5855d422 authored by AngeloGioacchino Del Regno's avatar AngeloGioacchino Del Regno Committed by Chun-Kuang Hu
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drm: mediatek: mtk_dsi: Fix NO_EOT_PACKET settings/handling 



Due to the initial confusion about MIPI_DSI_MODE_EOT_PACKET, properly
renamed to MIPI_DSI_MODE_NO_EOT_PACKET, reflecting its actual meaning,
both the DSI_TXRX_CON register setting for bit (HSTX_)DIS_EOT and the
later calculation for horizontal sync-active (HSA), back (HBP) and
front (HFP) porches got incorrect due to the logic being inverted.

This means that a number of settings were wrong because....:
 - DSI_TXRX_CON register setting: bit (HSTX_)DIS_EOT should be
   set in order to disable the End of Transmission packet;
 - Horizontal Sync and Back/Front porches: The delta used to
   calculate all of HSA, HBP and HFP should account for the
   additional EOT packet.

Before this change...
 - Bit (HSTX_)DIS_EOT was being set when EOT packet was enabled;
 - For HSA/HBP/HFP delta... all three were wrong, as words were
   added when EOT disabled, instead of when EOT packet enabled!

Invert the logic around flag MIPI_DSI_MODE_NO_EOT_PACKET in the
MediaTek DSI driver to fix the aforementioned issues.

Fixes: 8b2b99fd ("drm/mediatek: dsi: Fine tune the line time caused by EOTp")
Fixes: c87d1c4b ("drm/mediatek: dsi: Use symbolized register definition")
Signed-off-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: default avatarAlexandre Mergnat <amergnat@baylibre.com>
Tested-by: default avatarMichael Walle <mwalle@kernel.org>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230523104234.7849-1-angelogioacchino.delregno@collabora.com/


Signed-off-by: default avatarChun-Kuang Hu <chunkuang.hu@kernel.org>
parent 3f866041

drivers/gpu/drm/mediatek/mtk_dsi.c

+2 −2
Original line number Diff line number Diff line
@@ -409,7 +409,7 @@ static void mtk_dsi_rxtx_control(struct mtk_dsi *dsi) 
	if (dsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS)

		tmp_reg |= HSTX_CKLP_EN;



	if (!(dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET))

	if (dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)

		tmp_reg |= DIS_EOT;



	writel(tmp_reg, dsi->regs + DSI_TXRX_CTRL);
@@ -486,7 +486,7 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi) 
			  timing->da_hs_zero + timing->da_hs_exit + 3;



	delta = dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST ? 18 : 12;

	delta += dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET ? 2 : 0;

	delta += dsi->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET ? 0 : 2;



	horizontal_frontporch_byte = vm->hfront_porch * dsi_tmp_buf_bpp;

	horizontal_front_back_byte = horizontal_frontporch_byte + horizontal_backporch_byte;