5.4-stable review patch. If anyone has any objections, please let me know.
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From: Marek Szyprowski m.szyprowski@samsung.com
[ Upstream commit 5d91394f236167ac624b823820faf4aa928b889e ]
Commit c9b1150a68d9 ("drm/atomic-helper: Re-order bridge chain pre-enable and post-disable") changed the call sequence to the CRTC enable/disable and bridge pre_enable/post_disable methods, so those bridge methods are now called when CRTC is not yet enabled.
This causes a lockup observed on Samsung Peach-Pit/Pi Chromebooks. The source of this lockup is a call to fimd_dp_clock_enable() function, when FIMD device is not yet runtime resumed. It worked before the mentioned commit only because the CRTC implemented by the FIMD driver was always enabled what guaranteed the FIMD device to be runtime resumed.
This patch adds runtime PM guards to the fimd_dp_clock_enable() function to enable its proper operation also when the CRTC implemented by FIMD is not yet enabled.
Fixes: 196e059a8a6a ("drm/exynos: convert clock_enable crtc callback to pipeline clock") Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Tomi Valkeinen tomi.valkeinen@ideasonboard.com Signed-off-by: Inki Dae inki.dae@samsung.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/exynos/exynos_drm_fimd.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c index 4fe4ca41665b3..1978491d3f846 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c @@ -182,6 +182,7 @@ struct fimd_context { u32 i80ifcon; bool i80_if; bool suspended; + bool dp_clk_enabled; wait_queue_head_t wait_vsync_queue; atomic_t wait_vsync_event; atomic_t win_updated; @@ -1003,7 +1004,18 @@ static void fimd_dp_clock_enable(struct exynos_drm_clk *clk, bool enable) struct fimd_context *ctx = container_of(clk, struct fimd_context, dp_clk); u32 val = enable ? DP_MIE_CLK_DP_ENABLE : DP_MIE_CLK_DISABLE; + + if (enable == ctx->dp_clk_enabled) + return; + + if (enable) + pm_runtime_resume_and_get(ctx->dev); + + ctx->dp_clk_enabled = enable; writel(val, ctx->regs + DP_MIE_CLKCON); + + if (!enable) + pm_runtime_put(ctx->dev); }
static const struct exynos_drm_crtc_ops fimd_crtc_ops = {