5.15-stable review patch. If anyone has any objections, please let me know.
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From: Kaustabh Chakraborty kauschluss@disroot.org
[ Upstream commit 5f1a453974204175f20b3788824a0fe23cc36f79 ]
The DECON channels are not cleared properly as the windows aren't shadow protected. When accompanied with an IOMMU, it pagefaults, and the kernel panics.
Implement shadow protect/unprotect, along with a standalone update, for channel clearing to properly take effect.
Signed-off-by: Kaustabh Chakraborty kauschluss@disroot.org Signed-off-by: Inki Dae inki.dae@samsung.com Stable-dep-of: e1361a4f1be9 ("drm/exynos: exynos7_drm_decon: remove ctx->suspended") Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/exynos/exynos7_drm_decon.c | 55 ++++++++++++++++------------- 1 file changed, 32 insertions(+), 23 deletions(-)
--- a/drivers/gpu/drm/exynos/exynos7_drm_decon.c +++ b/drivers/gpu/drm/exynos/exynos7_drm_decon.c @@ -81,6 +81,28 @@ static const enum drm_plane_type decon_w DRM_PLANE_TYPE_CURSOR, };
+/** + * decon_shadow_protect_win() - disable updating values from shadow registers at vsync + * + * @ctx: display and enhancement controller context + * @win: window to protect registers for + * @protect: 1 to protect (disable updates) + */ +static void decon_shadow_protect_win(struct decon_context *ctx, + unsigned int win, bool protect) +{ + u32 bits, val; + + bits = SHADOWCON_WINx_PROTECT(win); + + val = readl(ctx->regs + SHADOWCON); + if (protect) + val |= bits; + else + val &= ~bits; + writel(val, ctx->regs + SHADOWCON); +} + static void decon_wait_for_vblank(struct decon_context *ctx) { if (ctx->suspended) @@ -101,18 +123,27 @@ static void decon_wait_for_vblank(struct static void decon_clear_channels(struct decon_context *ctx) { unsigned int win, ch_enabled = 0; + u32 val;
/* Check if any channel is enabled. */ for (win = 0; win < WINDOWS_NR; win++) { - u32 val = readl(ctx->regs + WINCON(win)); + val = readl(ctx->regs + WINCON(win));
if (val & WINCONx_ENWIN) { + decon_shadow_protect_win(ctx, win, true); + val &= ~WINCONx_ENWIN; writel(val, ctx->regs + WINCON(win)); ch_enabled = 1; + + decon_shadow_protect_win(ctx, win, false); } }
+ val = readl(ctx->regs + DECON_UPDATE); + val |= DECON_UPDATE_STANDALONE_F; + writel(val, ctx->regs + DECON_UPDATE); + /* Wait for vsync, as disable channel takes effect at next vsync */ if (ch_enabled) decon_wait_for_vblank(ctx); @@ -340,28 +371,6 @@ static void decon_win_set_colkey(struct writel(keycon1, ctx->regs + WKEYCON1_BASE(win)); }
-/** - * decon_shadow_protect_win() - disable updating values from shadow registers at vsync - * - * @ctx: display and enhancement controller context - * @win: window to protect registers for - * @protect: 1 to protect (disable updates) - */ -static void decon_shadow_protect_win(struct decon_context *ctx, - unsigned int win, bool protect) -{ - u32 bits, val; - - bits = SHADOWCON_WINx_PROTECT(win); - - val = readl(ctx->regs + SHADOWCON); - if (protect) - val |= bits; - else - val &= ~bits; - writel(val, ctx->regs + SHADOWCON); -} - static void decon_atomic_begin(struct exynos_drm_crtc *crtc) { struct decon_context *ctx = crtc->ctx;