Re: [PATCH v2 1/2] usb: typec: ucsi: Use GET_CAPABILITY attributes data to set power supply scope

[Greg Kroah-Hartman]

On Thu, Oct 05, 2023 at 12:52:29PM -0500, Mario Limonciello wrote:
> On some OEM systems, adding a W7900 dGPU triggers RAS errors and hangs
> at a black screen on startup.  This issue occurs only if `ucsi_acpi` has
> loaded before `amdgpu` has loaded.  The reason for this failure is that
> `amdgpu` uses power_supply_is_system_supplied() to determine if running
> on AC or DC power at startup. If this value is reported incorrectly the
> dGPU will also be programmed incorrectly and trigger errors.
> 
> power_supply_is_system_supplied() reports the wrong value because UCSI
> power supplies provided as part of the system don't properly report the
> scope as "DEVICE" scope (not powering the system).
> 
> In order to fix this issue check the capabilities reported from the UCSI
> power supply to ensure that it supports charging a battery and that it can
> be powered by AC.  Mark the scope accordingly.
> 
> Fixes: a7fbfd44c020 ("usb: typec: ucsi: Mark dGPUs as DEVICE scope")
> Link: https://www.intel.com/content/www/us/en/products/docs/io/universal-serial-bus/usb-type-c-ucsi-spec.html p28
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
> Cc: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> Cc: Alex Deucher <Alexander.Deucher@xxxxxxx>>
> Cc: Richard Gong <Richard.Gong@xxxxxxx>
> ---
>  drivers/usb/typec/ucsi/psy.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/usb/typec/ucsi/psy.c b/drivers/usb/typec/ucsi/psy.c
> index 384b42267f1f..b35c6e07911e 100644
> --- a/drivers/usb/typec/ucsi/psy.c
> +++ b/drivers/usb/typec/ucsi/psy.c
> @@ -37,6 +37,15 @@ static int ucsi_psy_get_scope(struct ucsi_connector *con,
>  	struct device *dev = con->ucsi->dev;
>  
>  	device_property_read_u8(dev, "scope", &scope);
> +	if (scope == POWER_SUPPLY_SCOPE_UNKNOWN) {
> +		u32 mask = UCSI_CAP_ATTR_POWER_AC_SUPPLY |
> +			   UCSI_CAP_ATTR_BATTERY_CHARGING;
> +
> +		if (con->ucsi->cap.attributes & mask)
> +			scope = POWER_SUPPLY_SCOPE_SYSTEM;
> +		else
> +			scope = POWER_SUPPLY_SCOPE_DEVICE;
> +	}
>  	val->intval = scope;
>  	return 0;
>  }
> -- 
> 2.34.1
> 
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
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- You have marked a patch with a "Fixes:" tag for a commit that is in an
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  Documentation/process/stable-kernel-rules.rst file for how to resolve
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If you wish to discuss this problem further, or you have questions about
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thanks,

greg k-h's patch email bot