Subject: [PATCH] PCI: imx6:don't sleep in atomic context

From: [email-masked] (Bjorn Helgaas)
Date: Wed, 6 Jan 2016 16:04:30 -0600

Hi Sanjeev,

On Mon, Nov 09, 2015 at 04:18:00PM +0530, Sanjeev Sharma wrote:
> If additional PCIe switch get connected between the
> host and the NIC,the kernel crashes with "BUG:
> scheduling while atomic". To handle this we need to
> call mdelay() instead of usleep_range().
> 
> For more detail please refer bugzilla.kernel.org, Bug
> 100031
> 
> Signed-off-by: Sanjeev Sharma <[email-masked]>
> Signed-off-by: David Mueller <[email-masked]>

I'm dropping this for now because we've been kicking around the same
solution (with tweaks to the mdelay amount) since June, but no
progress on the *real* issue, which is that imx6_pcie_link_up() should
never wait; it should simply return the link status.

I'm pretty sure the amount of time I've spent looking into this would
have been enough to make some progress on that underlying issue.

Bjorn

> ---
>  drivers/pci/host/pci-imx6.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
> index 233a196..9769b13 100644
> --- a/drivers/pci/host/pci-imx6.c
> +++ b/drivers/pci/host/pci-imx6.c
> @@ -499,7 +499,7 @@ static int imx6_pcie_link_up(struct pcie_port *pp)
>  		 * Wait a little bit, then re-check if the link finished
>  		 * the training.
>  		 */
> -		usleep_range(1000, 2000);
> +		mdelay(1000);
>  	}
>  	/*
>  	 * From L0, initiate MAC entry to gen2 if EP/RC supports gen2.
> -- 
> 1.7.11.7
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html