[linux-sunxi] [PATCH] drm: sun4i: exclusively set HDMI-related clocks for dw-hdmi

[Icenowy Zheng]

于 2018年8月15日 GMT+08:00 下午9:39:44, "Jernej Škrabec" <jernej.skrabec at gmail.com> 写到:
>Hi!
>
>Dne sreda, 15. avgust 2018 ob 14:07:45 CEST je Icenowy Zheng
>napisal(a):
>> The glue in sun4i-drm of dw-hdmi currently doesn't set the clocks of
>> dw-hdmi exclusively, which will lead the display fails to initialize
>in
>> some situations.
>> 
>> Add the exclusivity to sun8i-dw-hdmi and sun8i-hdmi-phy.
>> 
>> Cc: stable at vger.kernel.org # v4.17+
>> Signed-off-by: Icenowy Zheng <icenowy at aosc.io>
>
>Given that you want this patch to be merged in stable, I have to ask
>what kind 
>of tests did you run to prove it works as expected?
>
>In the past, there were some issues with TCON exclusive rate setting.
>It turns 
>out that as many scenarios as possible have to be tested before you can
>say 
>it's working.
>
>I imagine that it has to be tested on at least A83T, H3 (or H5) and R40
>(or 
>A64). They all have their own specifics which needs to be covered.
>
>Tests which I remember from top of my head:
>- run with monitor connected at boot

BTW I think the bootloader will affect the state of displsy even
without the patch.

When could your U-Boot tweaks patchset to be done? I think they will
be needed for a really reliable test.

>- run with monitor disconnected at boot and connect it later
>- playing with resolution switching (at least a few non-standard, e.g 
>something other than 1080p or 720p)

How to do it without starting a X server?

>
>Best regards,
>Jernej
>
>
>> ---
>>  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c  | 11 ++++++++++-
>>  drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c |  7 +++++--
>>  2 files changed, 15 insertions(+), 3 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
>> b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c index
>31875b636434..a10220518548
>> 100644
>> --- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
>> +++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
>> @@ -137,10 +137,16 @@ static int sun8i_dw_hdmi_bind(struct device
>*dev,
>> struct device *master, goto err_assert_ctrl_reset;
>>  	}
>> 
>> +	ret = clk_rate_exclusive_get(hdmi->clk_tmds);
>> +	if (ret) {
>> +		dev_err(dev, "Could not get exclusivity over the tmds clock\n");
>> +		goto err_disable_clk_tmds;
>> +	}
>> +
>>  	phy_node = of_parse_phandle(dev->of_node, "phys", 0);
>>  	if (!phy_node) {
>>  		dev_err(dev, "Can't found PHY phandle\n");
>> -		goto err_disable_clk_tmds;
>> +		goto err_put_clk_tmds_exclusivity;
>>  	}
>> 
>>  	ret = sun8i_hdmi_phy_probe(hdmi, phy_node);
>> @@ -179,6 +185,8 @@ static int sun8i_dw_hdmi_bind(struct device *dev,
>struct
>> device *master, cleanup_encoder:
>>  	drm_encoder_cleanup(encoder);
>>  	sun8i_hdmi_phy_remove(hdmi);
>> +err_put_clk_tmds_exclusivity:
>> +	clk_rate_exclusive_put(hdmi->clk_tmds);
>>  err_disable_clk_tmds:
>>  	clk_disable_unprepare(hdmi->clk_tmds);
>>  err_assert_ctrl_reset:
>> @@ -194,6 +202,7 @@ static void sun8i_dw_hdmi_unbind(struct device
>*dev,
>> struct device *master,
>> 
>>  	dw_hdmi_unbind(hdmi->hdmi);
>>  	sun8i_hdmi_phy_remove(hdmi);
>> +	clk_rate_exclusive_put(hdmi->clk_tmds);
>>  	clk_disable_unprepare(hdmi->clk_tmds);
>>  	reset_control_assert(hdmi->rst_ctrl);
>>  }
>> diff --git a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
>> b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c index
>82502b351aec..1e0b1d9bc0fb
>> 100644
>> --- a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
>> +++ b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
>> @@ -511,13 +511,14 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi
>*hdmi,
>> struct device_node *node) }
>> 
>>  		clk_prepare_enable(phy->clk_phy);
>> +		clk_rate_exclusive_get(phy->clk_phy);
>>  	}
>> 
>>  	phy->rst_phy = of_reset_control_get_shared(node, "phy");
>>  	if (IS_ERR(phy->rst_phy)) {
>>  		dev_err(dev, "Could not get phy reset control\n");
>>  		ret = PTR_ERR(phy->rst_phy);
>> -		goto err_disable_clk_phy;
>> +		goto err_put_clk_phy_exclusivity;
>>  	}
>> 
>>  	ret = reset_control_deassert(phy->rst_phy);
>> @@ -548,7 +549,8 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi
>*hdmi,
>> struct device_node *node) reset_control_assert(phy->rst_phy);
>>  err_put_rst_phy:
>>  	reset_control_put(phy->rst_phy);
>> -err_disable_clk_phy:
>> +err_put_clk_phy_exclusivity:
>> +	clk_rate_exclusive_put(phy->clk_phy);
>>  	clk_disable_unprepare(phy->clk_phy);
>>  err_put_clk_pll1:
>>  	clk_put(phy->clk_pll1);
>> @@ -568,6 +570,7 @@ void sun8i_hdmi_phy_remove(struct sun8i_dw_hdmi
>*hdmi)
>> 
>>  	clk_disable_unprepare(phy->clk_mod);
>>  	clk_disable_unprepare(phy->clk_bus);
>> +	clk_rate_exclusive_put(phy->clk_phy);
>>  	clk_disable_unprepare(phy->clk_phy);
>> 
>>  	reset_control_assert(phy->rst_phy);