From: Quanyang Wang quanyang.wang@windriver.com
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=...
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[ 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 quanyang.wang@windriver.com Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com --- 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");