2023-06-30 16:34:02

by Neil Armstrong

Subject: [PATCH v6 5/9] drm/meson: gate px_clk when setting rate

Disable the px_clk when setting the rate to recover a fully
configured and correctly reset VCLK clock tree after the rate
is set.

Fixes: 77d9e1e6b846 ("drm/meson: add support for MIPI-DSI transceiver")
Signed-off-by: Neil Armstrong <[email protected]>
---
drivers/gpu/drm/meson/meson_dw_mipi_dsi.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
index 57447abf1a29..dc63d2d813a9 100644
--- a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
+++ b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
@@ -94,6 +94,7 @@ static int dw_mipi_dsi_phy_init(void *priv_data)
return ret;
}

+ clk_disable_unprepare(mipi_dsi->px_clk);
ret = clk_set_rate(mipi_dsi->px_clk, mipi_dsi->mode->clock * 1000);

if (ret) {
@@ -102,6 +103,12 @@ static int dw_mipi_dsi_phy_init(void *priv_data)
return ret;
}

+ clk_prepare_enable(mipi_dsi->px_clk);
+ if (ret) {
+ dev_err(mipi_dsi->dev, "Failed to enable DSI Pixel clock (ret %d)\n", ret);
+ return ret;
+ }
+
switch (mipi_dsi->dsi_device->format) {
case MIPI_DSI_FMT_RGB888:
dpi_data_format = DPI_COLOR_24BIT;

--
2.34.1

2023-06-30 18:35:37

by George Stark

Subject: Re: [PATCH v6 5/9] drm/meson: gate px_clk when setting rate

Hello Neil

On 6/30/23 19:29, Neil Armstrong wrote:
> Disable the px_clk when setting the rate to recover a fully
> configured and correctly reset VCLK clock tree after the rate
> is set.
>
> Fixes: 77d9e1e6b846 ("drm/meson: add support for MIPI-DSI transceiver")
> Signed-off-by: Neil Armstrong <[email protected]>
> ---
> drivers/gpu/drm/meson/meson_dw_mipi_dsi.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
> index 57447abf1a29..dc63d2d813a9 100644
> --- a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
> @@ -94,6 +94,7 @@ static int dw_mipi_dsi_phy_init(void *priv_data)
> return ret;
> }
>
> + clk_disable_unprepare(mipi_dsi->px_clk);
> ret = clk_set_rate(mipi_dsi->px_clk, mipi_dsi->mode->clock * 1000);
>
> if (ret) {
> @@ -102,6 +103,12 @@ static int dw_mipi_dsi_phy_init(void *priv_data)
> return ret;
> }
>
> + clk_prepare_enable(mipi_dsi->px_clk);
probably should be:
ret = clk_prepare_enable(mipi_dsi->px_clk);
> + if (ret) {
> + dev_err(mipi_dsi->dev, "Failed to enable DSI Pixel clock (ret %d)\n", ret);
> + return ret;
> + }
> +
> switch (mipi_dsi->dsi_device->format) {
> case MIPI_DSI_FMT_RGB888:
> dpi_data_format = DPI_COLOR_24BIT;
>
--
Best regards
George

2023-07-03 07:33:39

by Neil Armstrong

Subject: Re: [PATCH v6 5/9] drm/meson: gate px_clk when setting rate

On 30/06/2023 20:10, George Stark wrote:
> Hello Neil
>
> On 6/30/23 19:29, Neil Armstrong wrote:
>> Disable the px_clk when setting the rate to recover a fully
>> configured and correctly reset VCLK clock tree after the rate
>> is set.
>>
>> Fixes: 77d9e1e6b846 ("drm/meson: add support for MIPI-DSI transceiver")
>> Signed-off-by: Neil Armstrong <[email protected]>
>> ---
>>   drivers/gpu/drm/meson/meson_dw_mipi_dsi.c | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
>> index 57447abf1a29..dc63d2d813a9 100644
>> --- a/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
>> +++ b/drivers/gpu/drm/meson/meson_dw_mipi_dsi.c
>> @@ -94,6 +94,7 @@ static int dw_mipi_dsi_phy_init(void *priv_data)
>>           return ret;
>>       }
>> +    clk_disable_unprepare(mipi_dsi->px_clk);
>>       ret = clk_set_rate(mipi_dsi->px_clk, mipi_dsi->mode->clock * 1000);
>>       if (ret) {
>> @@ -102,6 +103,12 @@ static int dw_mipi_dsi_phy_init(void *priv_data)
>>           return ret;
>>       }
>> +    clk_prepare_enable(mipi_dsi->px_clk);
> probably should be:
> ret = clk_prepare_enable(mipi_dsi->px_clk);

Indeed, thx for noticing :-)

>> +    if (ret) {
>> +        dev_err(mipi_dsi->dev, "Failed to enable DSI Pixel clock (ret %d)\n", ret);
>> +        return ret;
>> +    }
>> +
>>       switch (mipi_dsi->dsi_device->format) {
>>       case MIPI_DSI_FMT_RGB888:
>>           dpi_data_format = DPI_COLOR_24BIT;
>>