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From 289c29b96fcc6cbe5c966fb0cc9e1bb8efbdd9dc Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Thu, 26 Mar 2020 15:32:19 +0000
Subject: [PATCH] drm/vc4: Kick the core clock up during a mode change
Experimental commit to kick the core clock up during mode
switching. This makes mode switching far more reliable, and
mimics what the firmware does.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
arch/arm/boot/dts/bcm2711.dtsi | 1 +
drivers/gpu/drm/vc4/vc4_drv.h | 2 ++
drivers/gpu/drm/vc4/vc4_hvs.c | 7 +++++++
drivers/gpu/drm/vc4/vc4_kms.c | 6 ++++++
4 files changed, 16 insertions(+)
--- a/arch/arm/boot/dts/bcm2711.dtsi
+++ b/arch/arm/boot/dts/bcm2711.dtsi
@@ -306,6 +306,7 @@
};
hvs@7e400000 {
+ clocks = <&firmware_clocks 4>;
interrupts = <GIC_SPI 97 IRQ_TYPE_LEVEL_HIGH>;
};
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -326,6 +326,8 @@ struct vc4_hvs {
void __iomem *regs;
u32 __iomem *dlist;
+ struct clk *core_clk;
+
/* Memory manager for CRTCs to allocate space in the display
* list. Units are dwords.
*/
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -19,6 +19,7 @@
* each CRTC.
*/
+#include <linux/clk.h>
#include <linux/component.h>
#include <linux/platform_device.h>
@@ -239,6 +240,12 @@ static int vc4_hvs_bind(struct device *d
hvs->regset.regs = hvs_regs;
hvs->regset.nregs = ARRAY_SIZE(hvs_regs);
+ hvs->core_clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(hvs->core_clk)) {
+ dev_err(&pdev->dev, "Couldn't get core clock\n");
+ return PTR_ERR(hvs->regs);
+ }
+
hvs_version = readl(hvs->regs + SCALER_DISPLSTAT) >> 24;
if (hvs_version >= 0x40)
hvs->hvs5 = true;
--- a/drivers/gpu/drm/vc4/vc4_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_kms.c
@@ -13,6 +13,7 @@
#include <linux/bitfield.h>
#include <linux/bitops.h>
+#include <linux/clk.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
@@ -222,6 +223,7 @@ vc4_atomic_complete_commit(struct drm_at
{
struct drm_device *dev = state->dev;
struct vc4_dev *vc4 = to_vc4_dev(dev);
+ struct vc4_hvs *hvs = vc4->hvs;
struct vc4_crtc *vc4_crtc;
int i;
@@ -237,6 +239,8 @@ vc4_atomic_complete_commit(struct drm_at
vc4_hvs_mask_underrun(dev, vc4_crtc_state->assigned_channel);
}
+ clk_set_rate(hvs->core_clk, 500000000);
+
drm_atomic_helper_wait_for_fences(dev, state, false);
drm_atomic_helper_wait_for_dependencies(state);
@@ -262,6 +266,8 @@ vc4_atomic_complete_commit(struct drm_at
drm_atomic_helper_commit_cleanup_done(state);
+ clk_set_rate(hvs->core_clk, 200000000);
+
drm_atomic_state_put(state);
up(&vc4->async_modeset);
|
