Re: [PATCH v4 2/5] drm/msm/dsi: Adjust pclk rate for compression

[Jessica Zhang <quic_jesszhan@quicinc.com>]

On 5/22/2023 2:31 PM, Marijn Suijten wrote:
> On 2023-05-22 13:30:21, Jessica Zhang wrote:
>> Adjust the pclk rate to divide hdisplay by the compression ratio when DSC
>> is enabled.
>>
>> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
> 
> As discussed previously, this patch would apply a lot more cleanly on
> top of:
> 
> https://lore.kernel.org/linux-arm-msm/20230520200103.4019607-1-dmitry.baryshkov@linaro.org/T/#u
> 
> (This is the v2 that doesn't change the callback, but does change the
> code flow so that you have to *touch less lines* in this patch).

Hi Marijn,

Sounds good. I'll rebase on top of that.

Thanks,

Jessica Zhang

> 
> - Marijn
> 
>> ---
>>   drivers/gpu/drm/msm/dsi/dsi_host.c | 23 +++++++++++++++++++----
>>   1 file changed, 19 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
>> index 18d38b90eb28..d04f8bbd707d 100644
>> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
>> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
>> @@ -561,7 +561,18 @@ void dsi_link_clk_disable_v2(struct msm_dsi_host *msm_host)
>>   	clk_disable_unprepare(msm_host->byte_clk);
>>   }
>>   
>> -static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode, bool is_bonded_dsi)
>> +static unsigned long dsi_adjust_compressed_pclk(const struct drm_display_mode *mode,
>> +		const struct drm_dsc_config *dsc)
>> +{
>> +	int new_hdisplay = DIV_ROUND_UP(mode->hdisplay * drm_dsc_get_bpp_int(dsc),
>> +			dsc->bits_per_component * 3);
>> +
>> +	return (new_hdisplay + (mode->htotal - mode->hdisplay))
>> +			* mode->vtotal * drm_mode_vrefresh(mode);
>> +}
>> +
>> +static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode,
>> +		const struct drm_dsc_config *dsc, bool is_bonded_dsi)
>>   {
>>   	unsigned long pclk_rate;
>>   
>> @@ -576,6 +587,10 @@ static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode, bool
>>   	if (is_bonded_dsi)
>>   		pclk_rate /= 2;
>>   
>> +	/* If DSC is enabled, divide hdisplay by compression ratio */
>> +	if (dsc)
>> +		pclk_rate = dsi_adjust_compressed_pclk(mode, dsc);
>> +
>>   	return pclk_rate;
>>   }
>>   
>> @@ -585,7 +600,7 @@ unsigned long dsi_byte_clk_get_rate(struct mipi_dsi_host *host, bool is_bonded_d
>>   	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
>>   	u8 lanes = msm_host->lanes;
>>   	u32 bpp = dsi_get_bpp(msm_host->format);
>> -	unsigned long pclk_rate = dsi_get_pclk_rate(mode, is_bonded_dsi);
>> +	unsigned long pclk_rate = dsi_get_pclk_rate(mode, msm_host->dsc, is_bonded_dsi);
>>   	u64 pclk_bpp = (u64)pclk_rate * bpp;
>>   
>>   	if (lanes == 0) {
>> @@ -604,7 +619,7 @@ unsigned long dsi_byte_clk_get_rate(struct mipi_dsi_host *host, bool is_bonded_d
>>   
>>   static void dsi_calc_pclk(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>>   {
>> -	msm_host->pixel_clk_rate = dsi_get_pclk_rate(msm_host->mode, is_bonded_dsi);
>> +	msm_host->pixel_clk_rate = dsi_get_pclk_rate(msm_host->mode, msm_host->dsc, is_bonded_dsi);
>>   	msm_host->byte_clk_rate = dsi_byte_clk_get_rate(&msm_host->base, is_bonded_dsi,
>>   							msm_host->mode);
>>   
>> @@ -634,7 +649,7 @@ int dsi_calc_clk_rate_v2(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>>   
>>   	dsi_calc_pclk(msm_host, is_bonded_dsi);
>>   
>> -	pclk_bpp = (u64)dsi_get_pclk_rate(msm_host->mode, is_bonded_dsi) * bpp;
>> +	pclk_bpp = (u64)dsi_get_pclk_rate(msm_host->mode, msm_host->dsc, is_bonded_dsi) * bpp;
>>   	do_div(pclk_bpp, 8);
>>   	msm_host->src_clk_rate = pclk_bpp;
>>   
>>
>> -- 
>> 2.40.1
>>