On 16/11/2023 20:45, Jonathan Marek wrote:
On 11/15/23 2:38 AM, Dmitry Baryshkov wrote:
On Wed, 15 Nov 2023 at 01:00, Jonathan Marek <jonathan@xxxxxxxx> wrote:
Make it clear why the pkt_per_line value is being "divided by 2".
Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
---
drivers/gpu/drm/msm/dsi/dsi_host.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c
b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 66f198e21a7e..842765063b1b 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -877,6 +877,8 @@ static void dsi_update_dsc_timing(struct
msm_dsi_host *msm_host, bool is_cmd_mod
/* DSI_VIDEO_COMPRESSION_MODE & DSI_COMMAND_COMPRESSION_MODE
* registers have similar offsets, so for below common code use
* DSI_VIDEO_COMPRESSION_MODE_XXXX for setting bits
+ *
+ * pkt_per_line is log2 encoded, >>1 works for supported
values (1,2,4)
*/
reg |=
DSI_VIDEO_COMPRESSION_MODE_CTRL_PKT_PER_LINE(pkt_per_line >> 1);
Should we switch to ffs() or fls() instead?
Just a ffs() on its own can be confusing as well (without the
information that only powers of two are possible), I think like this is
better.
Sounds fair. Could you please then add `if (pkt_per_line > 4)
drm_warn("pkt_per_line too big");`
With that in place:
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
reg |=
DSI_VIDEO_COMPRESSION_MODE_CTRL_EOL_BYTE_NUM(eol_byte_num);
--
2.26.1
--
With best wishes
Dmitry
