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Subject[PATCH v3 034/105] drm/vc4: crtc: Add FIFO depth to vc4_crtc_data
Date
Not all pixelvalve FIFOs in vc5 have the same depth, so we need to add that
to our vc4_crtc_data structure to be able to compute the fill level
properly later on.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
drivers/gpu/drm/vc4/vc4_crtc.c | 19 ++++++++++++++++---
drivers/gpu/drm/vc4/vc4_drv.h | 3 +++
2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index a6c3f2f907bd..e25e81bf64e7 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -248,10 +248,20 @@ vc4_crtc_update_gamma_lut(struct drm_crtc *crtc)
vc4_crtc_lut_load(crtc);
}

-static u32 vc4_get_fifo_full_level(u32 format)
+static u32 vc4_get_fifo_full_level(struct vc4_crtc *vc4_crtc, u32 format)
{
- static const u32 fifo_len_bytes = 64;
+ u32 fifo_len_bytes = vc4_crtc->data->fifo_depth;

+ /*
+ * Pixels are pulled from the HVS if the number of bytes is
+ * lower than the FIFO full level.
+ *
+ * The latency of the pixel fetch mechanism is 6 pixels, so we
+ * need to convert those 6 pixels in bytes, depending on the
+ * format, and then subtract that from the length of the FIFO
+ * to make sure we never end up in a situation where the FIFO
+ * is full.
+ */
switch (format) {
case PV_CONTROL_FORMAT_DSIV_16:
case PV_CONTROL_FORMAT_DSIC_16:
@@ -367,7 +377,7 @@ static void vc4_crtc_config_pv(struct drm_crtc *crtc)

CRTC_WRITE(PV_CONTROL,
VC4_SET_FIELD(format, PV_CONTROL_FORMAT) |
- VC4_SET_FIELD(vc4_get_fifo_full_level(format),
+ VC4_SET_FIELD(vc4_get_fifo_full_level(vc4_crtc, format),
PV_CONTROL_FIFO_LEVEL) |
VC4_SET_FIELD(pixel_rep - 1, PV_CONTROL_PIXEL_REP) |
PV_CONTROL_CLR_AT_START |
@@ -1066,6 +1076,7 @@ static const struct vc4_crtc_data bcm2835_pv0_data = {
.hvs_available_channels = BIT(0),
.hvs_output = 0,
.debugfs_name = "crtc0_regs",
+ .fifo_depth = 64,
.pixels_per_clock = 1,
.encoder_types = {
[PV_CONTROL_CLK_SELECT_DSI] = VC4_ENCODER_TYPE_DSI0,
@@ -1077,6 +1088,7 @@ static const struct vc4_crtc_data bcm2835_pv1_data = {
.hvs_available_channels = BIT(2),
.hvs_output = 2,
.debugfs_name = "crtc1_regs",
+ .fifo_depth = 64,
.pixels_per_clock = 1,
.encoder_types = {
[PV_CONTROL_CLK_SELECT_DSI] = VC4_ENCODER_TYPE_DSI1,
@@ -1088,6 +1100,7 @@ static const struct vc4_crtc_data bcm2835_pv2_data = {
.hvs_available_channels = BIT(1),
.hvs_output = 1,
.debugfs_name = "crtc2_regs",
+ .fifo_depth = 64,
.pixels_per_clock = 1,
.encoder_types = {
[PV_CONTROL_CLK_SELECT_DPI_SMI_HDMI] = VC4_ENCODER_TYPE_HDMI,
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index 73156a53822f..1f62dffd6676 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -450,6 +450,9 @@ to_vc4_encoder(struct drm_encoder *encoder)
}

struct vc4_crtc_data {
+ /* Depth of the PixelValve FIFO in bytes */
+ unsigned int fifo_depth;
+
/* Which channels of the HVS can the output source from */
unsigned int hvs_available_channels;

--
git-series 0.9.1
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