From ebd267b2e3c25d5f93a08528b47c036569eb8744 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Sat, 29 Feb 2020 23:16:49 +0100 Subject: [PATCH] drm/stm: repair runtime power management MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add missing pm_runtime_get_sync() into ltdc_crtc_atomic_enable() to match pm_runtime_put_sync() in ltdc_crtc_atomic_disable(), otherwise the LTDC might suspend via runtime PM, disable clock, and then fail to resume later on. The test which triggers it is roughly -- run qt5 application which uses eglfs platform and etnaviv, stop the application, sleep for 15 minutes, run the application again. This leads to a timeout waiting for vsync, because the LTDC has suspended, but did not resume. Fixes: 35ab6cfbf211 ("drm/stm: support runtime power management") Signed-off-by: Marek Vasut Cc: Yannick Fertré Cc: Philippe Cornu Cc: Benjamin Gaignard Cc: Vincent Abriou Cc: Maxime Coquelin Cc: Alexandre Torgue To: dri-devel@lists.freedesktop.org Cc: linux-stm32@st-md-mailman.stormreply.com Cc: linux-arm-kernel@lists.infradead.org Acked-by: Philippe Cornu Tested-by: Yannick Fertre Signed-off-by: Benjamin Gaignard Link: https://patchwork.freedesktop.org/patch/msgid/20200229221649.90813-1-marex@denx.de --- drivers/gpu/drm/stm/ltdc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index ef77e1417ba8..6e28f707092f 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -423,9 +423,12 @@ static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc, struct drm_crtc_state *old_state) { struct ltdc_device *ldev = crtc_to_ltdc(crtc); + struct drm_device *ddev = crtc->dev; DRM_DEBUG_DRIVER("\n"); + pm_runtime_get_sync(ddev->dev); + /* Sets the background color value */ reg_write(ldev->regs, LTDC_BCCR, BCCR_BCBLACK);