| Message ID | 20200522101225.62571-1-jitao.shi@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/mediatek: dsi: fix scrolling of panel with small hfp or hbp | expand |
Hi, Jitao: Jitao Shi <jitao.shi@mediatek.com> 於 2020年5月22日 週五 下午6:12寫道： > > If panel has too small hfp or hbp, horizontal_frontporch_byte or > horizontal_backporch_byte may become very small value or negative > value. This patch adjusts their values so that they are greater > than minimum value and keep total of them unchanged. > > Signed-off-by: Jitao Shi <jitao.shi@mediatek.com> > --- > drivers/gpu/drm/mediatek/mtk_dsi.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c > index 0ede69830a9d..aebaafd90ceb 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > @@ -148,6 +148,9 @@ > (type == MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM) || \ > (type == MIPI_DSI_DCS_READ)) > > +#define MIN_HFP_BYTE 0x02 > +#define MIN_HBP_BYTE 0x02 > + > struct mtk_phy_timing { > u32 lpx; > u32 da_hs_prepare; > @@ -450,6 +453,7 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi) > u32 horizontal_sync_active_byte; > u32 horizontal_backporch_byte; > u32 horizontal_frontporch_byte; > + s32 signed_hfp_byte, signed_hbp_byte; > u32 dsi_tmp_buf_bpp, data_phy_cycles; > struct mtk_phy_timing *timing = &dsi->phy_timing; > > @@ -519,6 +523,20 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi) > } > } > > + signed_hfp_byte = (s32)horizontal_frontporch_byte; > + signed_hbp_byte = (s32)horizontal_backporch_byte; > + > + if (signed_hfp_byte + signed_hbp_byte < MIN_HFP_BYTE + MIN_HBP_BYTE) { > + DRM_WARN("Calculated hfp_byte and hbp_byte are too small, " > + "panel may not work properly.\n"); > + } else if (signed_hfp_byte < MIN_HFP_BYTE) { > + horizontal_frontporch_byte = MIN_HFP_BYTE; > + horizontal_backporch_byte -= MIN_HFP_BYTE - signed_hfp_byte; > + } else if (signed_hbp_byte < MIN_HBP_BYTE) { > + horizontal_frontporch_byte -= MIN_HBP_BYTE - signed_hbp_byte; > + horizontal_backporch_byte = MIN_HBP_BYTE; > + } > + I think horizontal_frontporch_byte would never be negtive, and horizontal_backporch_byte would be negtive when if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) horizontal_backporch_byte = (vm->hback_porch * dsi_tmp_buf_bpp - 10); else horizontal_backporch_byte = ((vm->hback_porch + vm->hsync_len) * dsi_tmp_buf_bpp - 10); If this time it's negtive, the calculation of horizontal_frontporch_byte is so strange. I think processing negtive value should before here. Regards, Chun-Kuang. > 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); > -- > 2.25.1 > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index 0ede69830a9d..aebaafd90ceb 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -148,6 +148,9 @@ (type == MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM) || \ (type == MIPI_DSI_DCS_READ)) +#define MIN_HFP_BYTE 0x02 +#define MIN_HBP_BYTE 0x02 + struct mtk_phy_timing { u32 lpx; u32 da_hs_prepare; @@ -450,6 +453,7 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi) u32 horizontal_sync_active_byte; u32 horizontal_backporch_byte; u32 horizontal_frontporch_byte; + s32 signed_hfp_byte, signed_hbp_byte; u32 dsi_tmp_buf_bpp, data_phy_cycles; struct mtk_phy_timing *timing = &dsi->phy_timing; @@ -519,6 +523,20 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi) } } + signed_hfp_byte = (s32)horizontal_frontporch_byte; + signed_hbp_byte = (s32)horizontal_backporch_byte; + + if (signed_hfp_byte + signed_hbp_byte < MIN_HFP_BYTE + MIN_HBP_BYTE) { + DRM_WARN("Calculated hfp_byte and hbp_byte are too small, " + "panel may not work properly.\n"); + } else if (signed_hfp_byte < MIN_HFP_BYTE) { + horizontal_frontporch_byte = MIN_HFP_BYTE; + horizontal_backporch_byte -= MIN_HFP_BYTE - signed_hfp_byte; + } else if (signed_hbp_byte < MIN_HBP_BYTE) { + horizontal_frontporch_byte -= MIN_HBP_BYTE - signed_hbp_byte; + horizontal_backporch_byte = MIN_HBP_BYTE; + } + 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);
If panel has too small hfp or hbp, horizontal_frontporch_byte or horizontal_backporch_byte may become very small value or negative value. This patch adjusts their values so that they are greater than minimum value and keep total of them unchanged. Signed-off-by: Jitao Shi <jitao.shi@mediatek.com> --- drivers/gpu/drm/mediatek/mtk_dsi.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)