drm/i915: Add comments about units of latency values

All the ILK+ WM compute functions take the latency values in 0.1us
units. Add a few comments to remind people about that.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Ville Syrjälä 2013-08-01 16:18:55 +03:00 committed by Daniel Vetter
parent b0aea5dca0
commit 37126462a4
1 changed files with 14 additions and 3 deletions

View File

@ -2123,6 +2123,7 @@ static uint32_t ilk_pipe_pixel_rate(struct drm_device *dev,
return pixel_rate;
}
/* latency must be in 0.1us units. */
static uint32_t ilk_wm_method1(uint32_t pixel_rate, uint8_t bytes_per_pixel,
uint32_t latency)
{
@ -2137,6 +2138,7 @@ static uint32_t ilk_wm_method1(uint32_t pixel_rate, uint8_t bytes_per_pixel,
return ret;
}
/* latency must be in 0.1us units. */
static uint32_t ilk_wm_method2(uint32_t pixel_rate, uint32_t pipe_htotal,
uint32_t horiz_pixels, uint8_t bytes_per_pixel,
uint32_t latency)
@ -2200,7 +2202,10 @@ enum hsw_data_buf_partitioning {
HSW_DATA_BUF_PART_5_6,
};
/* For both WM_PIPE and WM_LP. */
/*
* For both WM_PIPE and WM_LP.
* mem_value must be in 0.1us units.
*/
static uint32_t ilk_compute_pri_wm(struct hsw_pipe_wm_parameters *params,
uint32_t mem_value,
bool is_lp)
@ -2227,7 +2232,10 @@ static uint32_t ilk_compute_pri_wm(struct hsw_pipe_wm_parameters *params,
return min(method1, method2);
}
/* For both WM_PIPE and WM_LP. */
/*
* For both WM_PIPE and WM_LP.
* mem_value must be in 0.1us units.
*/
static uint32_t ilk_compute_spr_wm(struct hsw_pipe_wm_parameters *params,
uint32_t mem_value)
{
@ -2247,7 +2255,10 @@ static uint32_t ilk_compute_spr_wm(struct hsw_pipe_wm_parameters *params,
return min(method1, method2);
}
/* For both WM_PIPE and WM_LP. */
/*
* For both WM_PIPE and WM_LP.
* mem_value must be in 0.1us units.
*/
static uint32_t ilk_compute_cur_wm(struct hsw_pipe_wm_parameters *params,
uint32_t mem_value)
{