From aa7bf898d4bf921f61fab078040e8baec3f28126 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Sun, 19 Jul 2020 01:33:22 +0200 Subject: drm/mcde: Fix stability issue Whenever a display update was sent, apart from updating the memory base address, we called mcde_display_send_one_frame() which also sent a command to the display requesting the TE IRQ and enabling the FIFO. When continuous updates are running this is wrong: we need to only send this to start the flow to the display on the very first update. This lead to the display pipeline locking up and crashing. Check if the flow is already running and in that case do not call mcde_display_send_one_frame(). This fixes crashes on the Samsung GT-S7710 (Skomer). Signed-off-by: Linus Walleij Acked-by: Sam Ravnborg Acked-by: Stephan Gerhold Cc: Stephan Gerhold Cc: stable@vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20200718233323.3407670-1-linus.walleij@linaro.org --- drivers/gpu/drm/mcde/mcde_display.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm') diff --git a/drivers/gpu/drm/mcde/mcde_display.c b/drivers/gpu/drm/mcde/mcde_display.c index 08802e5177f6..4d2290f88edb 100644 --- a/drivers/gpu/drm/mcde/mcde_display.c +++ b/drivers/gpu/drm/mcde/mcde_display.c @@ -1060,9 +1060,14 @@ static void mcde_display_update(struct drm_simple_display_pipe *pipe, */ if (fb) { mcde_set_extsrc(mcde, drm_fb_cma_get_gem_addr(fb, pstate, 0)); - if (!mcde->video_mode) - /* Send a single frame using software sync */ - mcde_display_send_one_frame(mcde); + if (!mcde->video_mode) { + /* + * Send a single frame using software sync if the flow + * is not active yet. + */ + if (mcde->flow_active == 0) + mcde_display_send_one_frame(mcde); + } dev_info_once(mcde->dev, "sent first display update\n"); } else { /* -- cgit