Re: [PATCH v5 1/2] usb: ulpi: defer ulpi_register on ulpi_read_id timeout

[Heikki Krogerus]

On Mon, Dec 05, 2022 at 09:15:26PM +0100, Ferry Toth wrote:
> Since commit 0f0101719138 ("usb: dwc3: Don't switch OTG -> peripheral
> if extcon is present") Dual Role support on Intel Merrifield platform
> broke due to rearranging the call to dwc3_get_extcon().
> 
> It appears to be caused by ulpi_read_id() on the first test write failing
> with -ETIMEDOUT. Currently ulpi_read_id() expects to discover the phy via
> DT when the test write fails and returns 0 in that case, even if DT does not
> provide the phy. As a result usb probe completes without phy.
> 
> Make ulpi_read_id() return -ETIMEDOUT to its user if the first test write
> fails. The user should then handle it appropriately. A follow up patch
> will make dwc3_core_init() set -EPROBE_DEFER in this case and bail out.
> 
> Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Ferry Toth <ftoth@xxxxxxxxxxxxxx>

Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>

> ---
>  drivers/usb/common/ulpi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
> index d7c8461976ce..60e8174686a1 100644
> --- a/drivers/usb/common/ulpi.c
> +++ b/drivers/usb/common/ulpi.c
> @@ -207,7 +207,7 @@ static int ulpi_read_id(struct ulpi *ulpi)
>  	/* Test the interface */
>  	ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
>  	if (ret < 0)
> -		goto err;
> +		return ret;
>  
>  	ret = ulpi_read(ulpi, ULPI_SCRATCH);
>  	if (ret < 0)

thanks,

-- 
heikki