Re: [cip-dev] [PATCH for 5.10.y] phy: renesas: rcar-gen3-usb2: Fix the use of msleep during spinlock

[Pavel Machek <pavel@nabladev.com>]

[-- Attachment #1: Type: text/plain, Size: 1379 bytes --]

Hi!

> From: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
> 
> This fixes an issue caused by the use of msleep during spinlock.
> In the original commit, msleep was changed to mdelay, but this fix was not
> carried over during the backport to 5.10.y tree.

Doing this as a quick fix is probably okay, but this should not be
final version.

You are right that msleep inside spinlock will blow up immediately:

> ```
> [   62.677594] BUG: scheduling while atomic: kworker/1:2/126/0x00000002
> [   62.683957] Modules linked in:

But mdelay for 20 msec inside irqsave spinlock is borderline
unacceptable, too.

I believe we'll need Renesas to analyze/fix this properly after the
CVE emergency is done.

This fix is good for now, but better fix is needed.

Claudiu, are you right person for this, or should we cc someone else?

Best regards,
								Pavel


> index 5166a115879ea..90f2a0e5b2aa0 100644
> --- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> +++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> @@ -386,7 +386,7 @@ static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
>  	val = readl(usb2_base + USB2_ADPCTRL);
>  	writel(val | USB2_ADPCTRL_IDPULLUP, usb2_base + USB2_ADPCTRL);
>  
> -	msleep(20);
> +	mdelay(20);
>  
>  	writel(0xffffffff, usb2_base + USB2_OBINTSTA);
>  	writel(USB2_OBINT_BITS, usb2_base + USB2_OBINTEN);


-- 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]