Re: [PATCH v2] phy: stm32-usphyc: add mdelay(1) to fix timeout on some machines

[Sascha Hauer <sha@pengutronix.de>]

On Tue, Jan 24, 2023 at 09:44:34PM +0100, Michael Grzeschik wrote:
> An mdelay of 1 seems to be necessary on some machines, since
> the monsel status does not seem to be accurate. On rare occasions just
> working with the phy after this pll check lead to no functional usb.
> With this short mdelay this issue was not reported again.
> 
> Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
> ---
> v1 -> v2: - reworded the comment
> 

And updated to this one.

Sascha

>  drivers/phy/phy-stm32-usbphyc.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/phy/phy-stm32-usbphyc.c b/drivers/phy/phy-stm32-usbphyc.c
> index 657824405f..db4ccef920 100644
> --- a/drivers/phy/phy-stm32-usbphyc.c
> +++ b/drivers/phy/phy-stm32-usbphyc.c
> @@ -271,6 +271,15 @@ static int stm32_usbphyc_phy_init(struct phy *phy)
>  		goto pll_disable;
>  	}
>  
> +	/* This mdelay seems to be necessary on some machines, since the
> +	 * monsel status does not seem to be accurate. On rare occasions
> +	 * just working with the phy after this pll check the usb
> +	 * peripheral (e.g. on the dwc2) run into timeout issues and
> +	 * leading to no functional usb. With this short mdelay this
> +	 * issue was not reported again.
> +	 */
> +	mdelay(1);
> +
>  	usbphyc_phy->active = true;
>  
>  	return 0;
> -- 
> 2.30.2
> 
> 
> 

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