From: CK Hu ck.hu@mediatek.com
[ Upstream commit 487778f8d22fcdebb6436f0a5f96484ffa237b0b ]
In the patch to be fixed, horizontal_backporch_byte become too large for some panel, so roll back that patch. For small hfp or hbp panel, using vm->hfront_porch + vm->hback_porch to calculate horizontal_backporch_byte would make it negtive, so use horizontal_backporch_byte itself to make it positive.
Fixes: 35bf948f1edb ("drm/mediatek: dsi: Fix scrolling of panel with small hfp or hbp")
Signed-off-by: CK Hu ck.hu@mediatek.com Signed-off-by: Chun-Kuang Hu chunkuang.hu@kernel.org Tested-by: Bilal Wasim bilal.wasim@imgtec.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/mediatek/mtk_dsi.c | 61 +++++++++++------------------- 1 file changed, 22 insertions(+), 39 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index 80b7a082e8740..d6e0a29ea6b28 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -444,7 +444,10 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi) u32 horizontal_sync_active_byte; u32 horizontal_backporch_byte; u32 horizontal_frontporch_byte; + u32 horizontal_front_back_byte; + u32 data_phy_cycles_byte; u32 dsi_tmp_buf_bpp, data_phy_cycles; + u32 delta; struct mtk_phy_timing *timing = &dsi->phy_timing;
struct videomode *vm = &dsi->vm; @@ -466,50 +469,30 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi) horizontal_sync_active_byte = (vm->hsync_len * dsi_tmp_buf_bpp - 10);
if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) - horizontal_backporch_byte = vm->hback_porch * dsi_tmp_buf_bpp; + 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; + dsi_tmp_buf_bpp - 10;
data_phy_cycles = timing->lpx + timing->da_hs_prepare + - timing->da_hs_zero + timing->da_hs_exit; - - if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) { - if ((vm->hfront_porch + vm->hback_porch) * dsi_tmp_buf_bpp > - data_phy_cycles * dsi->lanes + 18) { - horizontal_frontporch_byte = - vm->hfront_porch * dsi_tmp_buf_bpp - - (data_phy_cycles * dsi->lanes + 18) * - vm->hfront_porch / - (vm->hfront_porch + vm->hback_porch); - - horizontal_backporch_byte = - horizontal_backporch_byte - - (data_phy_cycles * dsi->lanes + 18) * - vm->hback_porch / - (vm->hfront_porch + vm->hback_porch); - } else { - DRM_WARN("HFP less than d-phy, FPS will under 60Hz\n"); - horizontal_frontporch_byte = vm->hfront_porch * - dsi_tmp_buf_bpp; - } + timing->da_hs_zero + timing->da_hs_exit + 3; + + delta = dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST ? 18 : 12; + + horizontal_frontporch_byte = vm->hfront_porch * dsi_tmp_buf_bpp; + horizontal_front_back_byte = horizontal_frontporch_byte + horizontal_backporch_byte; + data_phy_cycles_byte = data_phy_cycles * dsi->lanes + delta; + + if (horizontal_front_back_byte > data_phy_cycles_byte) { + horizontal_frontporch_byte -= data_phy_cycles_byte * + horizontal_frontporch_byte / + horizontal_front_back_byte; + + horizontal_backporch_byte -= data_phy_cycles_byte * + horizontal_backporch_byte / + horizontal_front_back_byte; } else { - if ((vm->hfront_porch + vm->hback_porch) * dsi_tmp_buf_bpp > - data_phy_cycles * dsi->lanes + 12) { - horizontal_frontporch_byte = - vm->hfront_porch * dsi_tmp_buf_bpp - - (data_phy_cycles * dsi->lanes + 12) * - vm->hfront_porch / - (vm->hfront_porch + vm->hback_porch); - horizontal_backporch_byte = horizontal_backporch_byte - - (data_phy_cycles * dsi->lanes + 12) * - vm->hback_porch / - (vm->hfront_porch + vm->hback_porch); - } else { - DRM_WARN("HFP less than d-phy, FPS will under 60Hz\n"); - horizontal_frontporch_byte = vm->hfront_porch * - dsi_tmp_buf_bpp; - } + DRM_WARN("HFP + HBP less than d-phy, FPS will under 60Hz\n"); }
writel(horizontal_sync_active_byte, dsi->regs + DSI_HSA_WC);