Re: [PATCH RFC v2 5/6] drm/msm/dsi: Use MSM and DRM DSC helper methods

[Jessica Zhang <quic_jesszhan@quicinc.com>]

On 4/2/2023 4:29 AM, Dmitry Baryshkov wrote:
> On 31/03/2023 21:49, Jessica Zhang wrote:
>> Use MSM and DRM DSC helper methods to configure DSC for DSI.
>>
>> Changes in V2:
>> - *_calculate_initial_scale_value --> *_set_initial_scale_value
>> - Split pkt_per_line and eol_byte_num changes to a separate patch
>> - Moved pclk_per_line calculation to hdisplay adjustment in `if (dsc)`
>>    block of dsi_update_dsc_timing()
>>
>> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
>> ---
>>   drivers/gpu/drm/msm/dsi/dsi_host.c | 11 ++++++++---
>>   1 file changed, 8 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c 
>> b/drivers/gpu/drm/msm/dsi/dsi_host.c
>> index 74d38f90398a..b7ab81737473 100644
>> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
>> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
>> @@ -28,6 +28,7 @@
>>   #include "dsi.xml.h"
>>   #include "sfpb.xml.h"
>>   #include "dsi_cfg.h"
>> +#include "msm_dsc_helper.h"
>>   #include "msm_kms.h"
>>   #include "msm_gem.h"
>>   #include "phy/dsi_phy.h"
>> @@ -848,7 +849,7 @@ static void dsi_update_dsc_timing(struct 
>> msm_dsi_host *msm_host, bool is_cmd_mod
>>       /* first calculate dsc parameters and then program
>>        * compress mode registers
>>        */
>> -    slice_per_intf = DIV_ROUND_UP(hdisplay, dsc->slice_width);
>> +    slice_per_intf = msm_dsc_get_slice_per_intf(dsc, hdisplay);
>>       /*
>>        * If slice_count is greater than slice_per_intf
>> @@ -951,7 +952,11 @@ static void dsi_timing_setup(struct msm_dsi_host 
>> *msm_host, bool is_bonded_dsi)
>>            * pulse width same
>>            */
>>           h_total -= hdisplay;
>> -        hdisplay /= 3;
>> +        if (msm_host->mode_flags & MIPI_DSI_MODE_VIDEO)
>> +            hdisplay = msm_dsc_get_uncompressed_pclk_per_line(dsc, 
>> hdisplay,
>> +                    dsi_get_bpp(msm_host->format)) / 3;
>> +        else
>> +            hdisplay /= 3;
>>           h_total += hdisplay;
>>           ha_end = ha_start + hdisplay;
> 
> This chunk changes the calculated value (two other are mere updates to 
> use new functions). Please move it to a separate patch, add proper 
> description/justification and possibly a Fixes tag, if the original code 
> was incorrect.

Hi Dmitry,

Acked.

Thanks,

Jessica Zhang

> 
>>       }
>> @@ -1759,7 +1764,7 @@ static int dsi_populate_dsc_params(struct 
>> msm_dsi_host *msm_host, struct drm_dsc
>>           return ret;
>>       }
>> -    dsc->initial_scale_value = 32;
>> +    drm_dsc_set_initial_scale_value(dsc);
>>       dsc->line_buf_depth = dsc->bits_per_component + 1;
>>       return drm_dsc_compute_rc_parameters(dsc);
>>
> 
> -- 
> With best wishes
> Dmitry
>