[PATCH] mmc: omap_hsmmc: ensure probe returns error upon resource failure

[PATCH] mmc: omap_hsmmc: ensure probe returns error upon resource failure

[Kevin Hilman]

If platform_get_resource_by_name() fails, driver probe is aborted an
should return an error so the driver is not bound to the device.

However, in the current error path of platform_get_resource_by_name(),
probe returns zero since the return value (ret) is not properly set.
With a zero return value, the driver core assumes probe was successful
and will bind the driver to the device.

Fix this by ensuring that probe returns an error code in this failure
path.

Signed-off-by: Kevin Hilman <khilman@ti.com>
---
 drivers/mmc/host/omap_hsmmc.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 389a3ee..19e60e9 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -1931,6 +1931,7 @@ static int __devinit omap_hsmmc_probe(struct platform_device *pdev)
 	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx");
 	if (!res) {
 		dev_err(mmc_dev(host->mmc), "cannot get DMA TX channel\n");
+		ret = -ENXIO;
 		goto err_irq;
 	}
 	host->dma_line_tx = res->start;
@@ -1938,6 +1939,7 @@ static int __devinit omap_hsmmc_probe(struct platform_device *pdev)
 	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx");
 	if (!res) {
 		dev_err(mmc_dev(host->mmc), "cannot get DMA RX channel\n");
+		ret = -ENXIO;
 		goto err_irq;
 	}
 	host->dma_line_rx = res->start;
-- 
1.7.9.2

Re: [PATCH] mmc: omap_hsmmc: ensure probe returns error upon resource failure

[S, Venkatraman]

On Wed, Jul 11, 2012 at 5:10 AM, Kevin Hilman <khilman@ti.com> wrote:
> If platform_get_resource_by_name() fails, driver probe is aborted an
> should return an error so the driver is not bound to the device.
>
> However, in the current error path of platform_get_resource_by_name(),
> probe returns zero since the return value (ret) is not properly set.
> With a zero return value, the driver core assumes probe was successful
> and will bind the driver to the device.
>
> Fix this by ensuring that probe returns an error code in this failure
> path.
>
> Signed-off-by: Kevin Hilman <khilman@ti.com>

Good catch.
Acked-by: Venkatraman S <svenkatr@ti.com>


> ---
>  drivers/mmc/host/omap_hsmmc.c |    2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
> index 389a3ee..19e60e9 100644
> --- a/drivers/mmc/host/omap_hsmmc.c
> +++ b/drivers/mmc/host/omap_hsmmc.c
> @@ -1931,6 +1931,7 @@ static int __devinit omap_hsmmc_probe(struct platform_device *pdev)
>         res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx");
>         if (!res) {
>                 dev_err(mmc_dev(host->mmc), "cannot get DMA TX channel\n");
> +               ret = -ENXIO;
>                 goto err_irq;
>         }
>         host->dma_line_tx = res->start;
> @@ -1938,6 +1939,7 @@ static int __devinit omap_hsmmc_probe(struct platform_device *pdev)
>         res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx");
>         if (!res) {
>                 dev_err(mmc_dev(host->mmc), "cannot get DMA RX channel\n");
> +               ret = -ENXIO;
>                 goto err_irq;
>         }
>         host->dma_line_rx = res->start;
> --
> 1.7.9.2
>

Re: [PATCH] mmc: omap_hsmmc: ensure probe returns error upon resource failure

[Chris Ball]

Hi,

On Thu, Jul 12 2012, S, Venkatraman wrote:
> On Wed, Jul 11, 2012 at 5:10 AM, Kevin Hilman <khilman@ti.com> wrote:
>> If platform_get_resource_by_name() fails, driver probe is aborted an
>> should return an error so the driver is not bound to the device.
>>
>> However, in the current error path of platform_get_resource_by_name(),
>> probe returns zero since the return value (ret) is not properly set.
>> With a zero return value, the driver core assumes probe was successful
>> and will bind the driver to the device.
>>
>> Fix this by ensuring that probe returns an error code in this failure
>> path.
>>
>> Signed-off-by: Kevin Hilman <khilman@ti.com>
>
> Good catch.
> Acked-by: Venkatraman S <svenkatr@ti.com>

Thanks, pushed to mmc-next for 3.6.

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child