Subject: Re: [PATCH] sh_eth: ensure pm_runtime cannot suspend the device during init

From: Sergei Shtylyov <[email-masked]>
Date: Mon, 17 Mar 2014 17:01:09 +0400

Hello.

On 17-03-2014 15:37, Ben Dooks wrote:

> The pm_rumtime work queue is causing the device to be suspended during
> initialisation, thus the initialisation may not be able to access registers
> properly. As the code is called from a work queue, it is possible that this
> is not seen from certain configurations/builds due to the asynchronos
> nature of the code.

> Use pm_runtime_get_sync() and pm_runtime_put_sync() to ensure that the
> pm system does not suspend it during the probe() call and remove the
> now unnecessary pm_runtime_resume() call.

> This fixes the external abort that can cause /sbin/init or other such
> init processed to die.

> Signed-off-by: Ben Dooks <[email-masked]>
> Tested-by: Geert Uytterhoeven <[email-masked]>
> ---
>   drivers/net/ethernet/renesas/sh_eth.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)

> diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
> index 4f76b5e..f1cfd64 100644
> --- a/drivers/net/ethernet/renesas/sh_eth.c
> +++ b/drivers/net/ethernet/renesas/sh_eth.c
[...]
> @@ -2961,6 +2961,7 @@ static int sh_eth_drv_probe(struct platform_device *pdev)
>   	pr_info("Base address at 0x%x, %pM, IRQ %d.\n",
>   		(u32)ndev->base_addr, ndev->dev_addr, ndev->irq);
>
> +	pm_runtime_put_sync(&pdev->dev);

    I think you forgot to also do that on error cleanup path.

>   	platform_set_drvdata(pdev, ndev);
>
>   	return ret;

WBR, Sergei