From 6eccb5fb65507f59ef53aa661bb88293162cc62f Mon Sep 17 00:00:00 2001 From: Quanyang Wang Date: Thu, 21 Oct 2021 21:04:37 +0800 Subject: [PATCH] drm: xlnx: zynqmp_dpsub: Call pm_runtime_get_sync before setting pixel clock stable inclusion from stable-5.10.67 commit f76f78f9f479ebfdd94ec8c868b39aba7ca4fb0f bugzilla: 182619 https://gitee.com/openeuler/kernel/issues/I4EWO7 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f76f78f9f479ebfdd94ec8c868b39aba7ca4fb0f -------------------------------- [ Upstream commit a19effb6dbe5bd1be77a6d68eba04dba8993ffeb ] The Runtime PM subsystem will force the device "fd4a0000.zynqmp-display" to enter suspend state while booting if the following conditions are met: - the usage counter is zero (pm_runtime_get_sync hasn't been called yet) - no 'active' children (no zynqmp-dp-snd-xx node under dpsub node) - no other device in the same power domain (dpdma node has no "power-domains = <&zynqmp_firmware PD_DP>" property) So there is a scenario as below: 1) DP device enters suspend state <- call zynqmp_gpd_power_off 2) zynqmp_disp_crtc_setup_clock <- configurate register VPLL_FRAC_CFG 3) pm_runtime_get_sync <- call zynqmp_gpd_power_on and clear previous VPLL_FRAC_CFG configuration 4) clk_prepare_enable(disp->pclk) <- enable failed since VPLL_FRAC_CFG configuration is corrupted From above, we can see that pm_runtime_get_sync may clear register VPLL_FRAC_CFG configuration and result the failure of clk enabling. Putting pm_runtime_get_sync at the very beginning of the function zynqmp_disp_crtc_atomic_enable can resolve this issue. Signed-off-by: Quanyang Wang Reviewed-by: Laurent Pinchart Signed-off-by: Laurent Pinchart Signed-off-by: Sasha Levin Signed-off-by: Chen Jun Acked-by: Weilong Chen Signed-off-by: Chen Jun Signed-off-by: Zheng Zengkai --- drivers/gpu/drm/xlnx/zynqmp_disp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c index 8cd8af35cfaa..205c72a249b7 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c @@ -1447,9 +1447,10 @@ zynqmp_disp_crtc_atomic_enable(struct drm_crtc *crtc, struct drm_display_mode *adjusted_mode = &crtc->state->adjusted_mode; int ret, vrefresh; + pm_runtime_get_sync(disp->dev); + zynqmp_disp_crtc_setup_clock(crtc, adjusted_mode); - pm_runtime_get_sync(disp->dev); ret = clk_prepare_enable(disp->pclk); if (ret) { dev_err(disp->dev, "failed to enable a pixel clock\n"); -- GitLab