diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.14/950-0128-panel-raspberrypi-touchscreen-Round-up-clk-rate-to-f.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.14/950-0128-panel-raspberrypi-touchscreen-Round-up-clk-rate-to-f.patch | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.14/950-0128-panel-raspberrypi-touchscreen-Round-up-clk-rate-to-f.patch b/target/linux/brcm2708/patches-4.14/950-0128-panel-raspberrypi-touchscreen-Round-up-clk-rate-to-f.patch new file mode 100644 index 0000000000..a61dc66bf6 --- /dev/null +++ b/target/linux/brcm2708/patches-4.14/950-0128-panel-raspberrypi-touchscreen-Round-up-clk-rate-to-f.patch @@ -0,0 +1,35 @@ +From 7f98947db09ad419ca73082230ade1f29f18bd82 Mon Sep 17 00:00:00 2001 +From: Eric Anholt <eric@anholt.net> +Date: Mon, 6 Mar 2017 12:17:16 -0800 +Subject: [PATCH 128/454] panel-raspberrypi-touchscreen: Round up clk rate to + fix DSI panel. + +Commit 488f9bc8e3def93e0baef53cee2026c2cb0d8956 slightly increased the +reported rate of PLLD, so the clk driver decided that PLLD/3/8 was now +higher than our requested pixel clock rate and rejected it in favor of +PLLD/4/8, which then ran the pixel clock way out of spec. + +By bumping the requested clock rate just slightly, we get back to +PLLD/3/8 like we wanted and the panel displays content again. + +Signed-off-by: Eric Anholt <eric@anholt.net> +--- + drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c | 7 ++++++- + 1 file changed, 6 insertions(+), 1 deletion(-) + +--- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c ++++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c +@@ -220,7 +220,12 @@ static const struct drm_display_mode rpi + #define HBP 46 + #define HFP ((PIXEL_CLOCK / (VTOTAL * VREFRESH)) - (HACT + HSW + HBP)) + +- .clock = PIXEL_CLOCK / 1000, ++ /* Round up the pixel clock a bit (10khz), so that the ++ * "don't run things faster than the requested clock ++ * rate" rule of the clk driver doesn't reject the ++ * divide-by-3 mode due to rounding error. ++ */ ++ .clock = PIXEL_CLOCK / 1000 + 10, + .hdisplay = HACT, + .hsync_start = HACT + HFP, + .hsync_end = HACT + HFP + HSW, |