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.
Reviewed-by: Eric Anholt eric@anholt.net Signed-off-by: Maxime Ripard maxime@cerno.tech --- drivers/gpu/drm/vc4/vc4_crtc.c | 20 +++++++++++++++++--- drivers/gpu/drm/vc4/vc4_drv.h | 3 +++ 2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index b7e47ce1476c..2c64efd2d3d9 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -206,10 +206,21 @@ void vc4_crtc_destroy(struct drm_crtc *crtc) drm_crtc_cleanup(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; + const struct vc4_pv_data *pv_data = vc4_crtc_to_vc4_pv_data(vc4_crtc); + u32 fifo_len_bytes = pv_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: @@ -326,7 +337,7 @@ 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 | @@ -785,6 +796,7 @@ static const struct vc4_pv_data bcm2835_pv0_data = { .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, @@ -798,6 +810,7 @@ static const struct vc4_pv_data bcm2835_pv1_data = { .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, @@ -811,6 +824,7 @@ static const struct vc4_pv_data bcm2835_pv2_data = { .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 9e81ad8331f1..179010b9a010 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.h +++ b/drivers/gpu/drm/vc4/vc4_drv.h @@ -457,6 +457,9 @@ struct vc4_crtc_data { struct vc4_pv_data { struct vc4_crtc_data base;
+ /* Depth of the PixelValve FIFO in bytes */ + unsigned int fifo_depth; + /* Number of pixels output per clock period */ u8 pixels_per_clock;