Re: Tegra DRM with HDMI support (\o/)

[Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>]

On 10/16/2012 07:32 PM, Mark Zhang wrote:
> On 10/17/2012 12:03 AM, Stephen Warren wrote:
>> On 10/16/2012 02:18 AM, Mark Zhang wrote:
>>> Hi,
>>>
>>> I've made this drm driver worked on Tegra 3(LVDS and HDMI both).
>>> But the code that Thierry
>>> hosts(git://gitorious.org/thierryreding/linux.git) doesn't work
>>> directly. If you build and run it, you'll get a white blank screen on
>>> Tegra 3. I didn't find the root cause but I think this is not caused by
>>> drm driver itself(maybe the PCIE codes?). The main symptom is: some
>>> regulators can't be inited all the time. I tried to build drm driver as
>>> kernel module, after kernel booted, modprobe the drm driver, and you'll
>>> find there are a lot of error prints like this:
>>>
>>> =========================================================
>>> [   21.383529] reg-fixed-voltage 1.regulator: Failed to find supply vin
>>> [   21.390299] reg-fixed-voltage 1.regulator: Failed to register
>>> regulator: -517
>>> [   21.397645] platform 1.regulator: Driver reg-fixed-voltage requests
>>> probe deferral
>>> [   21.405604] platform 2.regulator: Driver reg-fixed-voltage requests
>>> probe deferral
>>> =========================================================
>>
>> This is normal; it's probe deferral. You'll find that those regulators
>> initialize correctly later. Hopefully tegra-drm handles this correctly,
>> and passes that error code through as the result of its probe.
>>
> 
> I don't think so. In normal scenario, the regulator will be inited
> correctly finally. But in the scenario I described above, these
> regulators will not be inited correctly all the time. Just as I
> mentioned above, I tried to build drm driver as kernel module, that
> means I will load drm driver after kernel booting finished. Besides,
> during the loading of drm driver, these regulator probe error were still
> be printed out. And I'm sure this is not the normal case.

The Cardhu PMIC driver isn't enabled in tegra_defconfig in Thierry's
branch. Do this:

> diff --git a/arch/arm/configs/tegra_defconfig b/arch/arm/configs/tegra_defconfig
> index c2a2f6e..90f4d5c 100644
> --- a/arch/arm/configs/tegra_defconfig
> +++ b/arch/arm/configs/tegra_defconfig
> @@ -124,16 +124,19 @@ CONFIG_SPI_OCORES=m
>  CONFIG_GPIO_SYSFS=y
>  CONFIG_GPIO_ADNP=y
>  CONFIG_GPIO_TPS6586X=y
> +CONFIG_GPIO_TPS65910=y
>  CONFIG_POWER_SUPPLY=y
>  CONFIG_BATTERY_SBS=y
>  CONFIG_SENSORS_LM90=y
> -CONFIG_SENSORS_ADC081C=m
>  CONFIG_MFD_TPS6586X=y
> +CONFIG_MFD_TPS65910=y
>  CONFIG_REGULATOR=y
>  CONFIG_REGULATOR_FIXED_VOLTAGE=y
>  CONFIG_REGULATOR_VIRTUAL_CONSUMER=y
>  CONFIG_REGULATOR_GPIO=y
> +CONFIG_REGULATOR_TPS62360=y
>  CONFIG_REGULATOR_TPS6586X=y
> +CONFIG_REGULATOR_TPS65910=y
>  CONFIG_DRM=m
>  CONFIG_DRM_TEGRA=m
>  CONFIG_DRM_TEGRA_DEBUG=y
> @@ -172,7 +175,7 @@ CONFIG_RTC_CLASS=y
>  CONFIG_RTC_INTF_SYSFS=y
>  CONFIG_RTC_INTF_PROC=y
>  CONFIG_RTC_INTF_DEV=y
> -CONFIG_RTC_DRV_PCF8523=y
> +CONFIG_RTC_DRV_TPS65910=y
>  CONFIG_RTC_DRV_TEGRA=y
>  CONFIG_DMADEVICES=y
>  CONFIG_TEGRA20_APB_DMA=y

(That still doesn't make tegradrm work for me on Cardhu, but it does
solve the regulator issue)