[PATCH] drivers: net: xgene: Fix crash on DT systems

[PATCH] drivers: net: xgene: Fix crash on DT systems

[Alban Bedel]

On DT systems the driver require a clock, but the probe just print a
warning and continue, leading to a crash when resetting the device.
To fix this crash and properly handle probe deferals only ignore the
missing clock if DT isn't used or if the clock doesn't exist.

Signed-off-by: Alban Bedel <alban.bedel@avionic-design.de>
---
 drivers/net/ethernet/apm/xgene/xgene_enet_main.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
index d0d0d12b531f..68b48edc5921 100644
--- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
@@ -1756,6 +1756,12 @@ static int xgene_enet_get_resources(struct xgene_enet_pdata *pdata)
 
 	pdata->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(pdata->clk)) {
+		/* Abort if the clock is defined but couldn't be retrived.
+		 * Always abort if the clock is missing on DT system as
+		 * the driver can't cope with this case.
+		 */
+		if (PTR_ERR(pdata->clk) != -ENOENT || dev->of_node)
+			return PTR_ERR(pdata->clk);
 		/* Firmware may have set up the clock already. */
 		dev_info(dev, "clocks have been setup already\n");
 	}
-- 
2.11.0

Re: [PATCH] drivers: net: xgene: Fix crash on DT systems

[Iyappan Subramanian]

On Tue, Feb 28, 2017 at 9:08 AM, Alban Bedel
<alban.bedel@avionic-design.de> wrote:
> On DT systems the driver require a clock, but the probe just print a
> warning and continue, leading to a crash when resetting the device.
> To fix this crash and properly handle probe deferals only ignore the
> missing clock if DT isn't used or if the clock doesn't exist.
>
> Signed-off-by: Alban Bedel <alban.bedel@avionic-design.de>
> ---
>  drivers/net/ethernet/apm/xgene/xgene_enet_main.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
> index d0d0d12b531f..68b48edc5921 100644
> --- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
> +++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
> @@ -1756,6 +1756,12 @@ static int xgene_enet_get_resources(struct xgene_enet_pdata *pdata)
>
>         pdata->clk = devm_clk_get(&pdev->dev, NULL);
>         if (IS_ERR(pdata->clk)) {
> +               /* Abort if the clock is defined but couldn't be retrived.
> +                * Always abort if the clock is missing on DT system as
> +                * the driver can't cope with this case.
> +                */
> +               if (PTR_ERR(pdata->clk) != -ENOENT || dev->of_node)
> +                       return PTR_ERR(pdata->clk);
>                 /* Firmware may have set up the clock already. */
>                 dev_info(dev, "clocks have been setup already\n");
>         }
> --
> 2.11.0
>

Thanks, Alban.

Acked-by: Iyappan Subramanian <isubramanian@apm.com>

Re: [PATCH] drivers: net: xgene: Fix crash on DT systems

[David Miller]

From: Alban Bedel <alban.bedel@avionic-design.de>
Date: Tue, 28 Feb 2017 18:08:55 +0100

> On DT systems the driver require a clock, but the probe just print a
> warning and continue, leading to a crash when resetting the device.
> To fix this crash and properly handle probe deferals only ignore the
> missing clock if DT isn't used or if the clock doesn't exist.
> 
> Signed-off-by: Alban Bedel <alban.bedel@avionic-design.de>

Applied, thanks.