[PATCH 5.18 289/879] drm/vc4: hvs: Fix frame count register readout

Greg Kroah-Hartman
2022-06-07T22:37:01Z

From: Maxime Ripard <maxime@cerno.tech>

[ Upstream commit b51cd7ad143d2eb31a6df81c2183128920e47c2b ]

In order to get the field currently being output, the driver has been
using the display FIFO frame count in the HVS, reading a 6-bit field at
the offset 12 in the DISPSTATx register.

While that field is indeed at that location for the FIFO 1 and 2, the
one for the FIFO0 is actually in the DISPSTAT1 register, at the offset
18.

Fixes: e538092cb15c ("drm/vc4: Enable precise vblank timestamping for interlaced modes.")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20220331143744.777652-3-maxime@cerno.tech
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/vc4/vc4_crtc.c | 2 +-
drivers/gpu/drm/vc4/vc4_drv.h | 1 +
drivers/gpu/drm/vc4/vc4_hvs.c | 23 +++++++++++++++++++++++
drivers/gpu/drm/vc4/vc4_regs.h | 12 ++++++++++--
4 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 783890e8d43a..477b3c5ad089 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -123,7 +123,7 @@ static bool vc4_crtc_get_scanout_position(struct drm_crtc *crtc,
*vpos /= 2;

/* Use hpos to correct for field offset in interlaced mode. */
- if (VC4_GET_FIELD(val, SCALER_DISPSTATX_FRAME_COUNT) % 2)
+ if (vc4_hvs_get_fifo_frame_count(dev, vc4_crtc_state->assigned_channel) % 2)
*hpos += mode->crtc_htotal / 2;
}

diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index 4329e09d357c..801da3e8ebdb 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -935,6 +935,7 @@ void vc4_irq_reset(struct drm_device *dev);
extern struct platform_driver vc4_hvs_driver;
void vc4_hvs_stop_channel(struct drm_device *dev, unsigned int output);
int vc4_hvs_get_fifo_from_output(struct drm_device *dev, unsigned int output);
+u8 vc4_hvs_get_fifo_frame_count(struct drm_device *dev, unsigned int fifo);
int vc4_hvs_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *state);
void vc4_hvs_atomic_begin(struct drm_crtc *crtc, struct drm_atomic_state *state);
void vc4_hvs_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_state *state);
diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index 604933e20e6a..c8cae10500b9 100644
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -197,6 +197,29 @@ static void vc4_hvs_update_gamma_lut(struct drm_crtc *crtc)
vc4_hvs_lut_load(crtc);
}

+u8 vc4_hvs_get_fifo_frame_count(struct drm_device *dev, unsigned int fifo)
+{
+ struct vc4_dev *vc4 = to_vc4_dev(dev);
+ u8 field = 0;
+
+ switch (fifo) {
+ case 0:
+ field = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTAT1),
+ SCALER_DISPSTAT1_FRCNT0);
+ break;
+ case 1:
+ field = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTAT1),
+ SCALER_DISPSTAT1_FRCNT1);
+ break;
+ case 2:
+ field = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTAT2),
+ SCALER_DISPSTAT2_FRCNT2);
+ break;
+ }
+
+ return field;
+}
+
int vc4_hvs_get_fifo_from_output(struct drm_device *dev, unsigned int output)
{
struct vc4_dev *vc4 = to_vc4_dev(dev);
diff --git a/drivers/gpu/drm/vc4/vc4_regs.h b/drivers/gpu/drm/vc4/vc4_regs.h
index 33410718089e..bae8c9cd6f7c 100644
--- a/drivers/gpu/drm/vc4/vc4_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_regs.h
@@ -379,8 +379,6 @@
# define SCALER_DISPSTATX_MODE_EOF 3
# define SCALER_DISPSTATX_FULL BIT(29)
# define SCALER_DISPSTATX_EMPTY BIT(28)
-# define SCALER_DISPSTATX_FRAME_COUNT_MASK VC4_MASK(17, 12)
-# define SCALER_DISPSTATX_FRAME_COUNT_SHIFT 12
# define SCALER_DISPSTATX_LINE_MASK VC4_MASK(11, 0)
# define SCALER_DISPSTATX_LINE_SHIFT 0

@@ -403,9 +401,15 @@
(x) * (SCALER_DISPBKGND1 - \
SCALER_DISPBKGND0))
#define SCALER_DISPSTAT1 0x00000058
+# define SCALER_DISPSTAT1_FRCNT0_MASK VC4_MASK(23, 18)
+# define SCALER_DISPSTAT1_FRCNT0_SHIFT 18
+# define SCALER_DISPSTAT1_FRCNT1_MASK VC4_MASK(17, 12)
+# define SCALER_DISPSTAT1_FRCNT1_SHIFT 12
+
#define SCALER_DISPSTATX(x) (SCALER_DISPSTAT0 + \
(x) * (SCALER_DISPSTAT1 - \
SCALER_DISPSTAT0))
+
#define SCALER_DISPBASE1 0x0000005c
#define SCALER_DISPBASEX(x) (SCALER_DISPBASE0 + \
(x) * (SCALER_DISPBASE1 - \
@@ -415,7 +419,11 @@
(x) * (SCALER_DISPCTRL1 - \
SCALER_DISPCTRL0))
#define SCALER_DISPBKGND2 0x00000064
+
#define SCALER_DISPSTAT2 0x00000068
+# define SCALER_DISPSTAT2_FRCNT2_MASK VC4_MASK(17, 12)
+# define SCALER_DISPSTAT2_FRCNT2_SHIFT 12
+
#define SCALER_DISPBASE2 0x0000006c
#define SCALER_DISPALPHA2 0x00000070
#define SCALER_GAMADDR 0x00000078
--
2.35.1