soc: aspeed: fix probe error handling
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Message ID 20190619125636.1109665-1-arnd@arndb.de
State Superseded, archived
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Series
  • soc: aspeed: fix probe error handling
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Commit Message

Arnd Bergmann June 19, 2019, 12:56 p.m. UTC
gcc warns that a mising "flash" phandle node leads to undefined
behavior later:

drivers/soc/aspeed/aspeed-lpc-ctrl.c: In function 'aspeed_lpc_ctrl_probe':
drivers/soc/aspeed/aspeed-lpc-ctrl.c:201:18: error: '*((void *)&resm+8)' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The device cannot work without this node, so just error out here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/soc/aspeed/aspeed-lpc-ctrl.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Joel Stanley June 20, 2019, 8:29 a.m. UTC | #1
On Wed, 19 Jun 2019 at 12:56, Arnd Bergmann <arnd@arndb.de> wrote:
>
> gcc warns that a mising "flash" phandle node leads to undefined
> behavior later:
>
> drivers/soc/aspeed/aspeed-lpc-ctrl.c: In function 'aspeed_lpc_ctrl_probe':
> drivers/soc/aspeed/aspeed-lpc-ctrl.c:201:18: error: '*((void *)&resm+8)' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>
> The device cannot work without this node, so just error out here.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks Arnd. This looks like it applies on top of Vijay's recent patch?

The intent of that change was to make the driver usable for systems
that do not want to depend on the flash phandle. I think the fix we
want looks like this:

--- a/drivers/soc/aspeed/aspeed-lpc-ctrl.c
+++ b/drivers/soc/aspeed/aspeed-lpc-ctrl.c
@@ -224,10 +224,11 @@ static int aspeed_lpc_ctrl_probe(struct
platform_device *pdev)
                        dev_err(dev, "Couldn't address to resource for
flash\n");
                        return rc;
                }
+
+               lpc_ctrl->pnor_size = resource_size(&resm);
+               lpc_ctrl->pnor_base = resm.start;
        }

-       lpc_ctrl->pnor_size = resource_size(&resm);
-       lpc_ctrl->pnor_base = resm.start;


Vijay, do you agree?

Cheers,

Joel

> ---
>  drivers/soc/aspeed/aspeed-lpc-ctrl.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/soc/aspeed/aspeed-lpc-ctrl.c b/drivers/soc/aspeed/aspeed-lpc-ctrl.c
> index 239520bb207e..81109d22af6a 100644
> --- a/drivers/soc/aspeed/aspeed-lpc-ctrl.c
> +++ b/drivers/soc/aspeed/aspeed-lpc-ctrl.c
> @@ -212,6 +212,7 @@ static int aspeed_lpc_ctrl_probe(struct platform_device *pdev)
>         node = of_parse_phandle(dev->of_node, "flash", 0);
>         if (!node) {
>                 dev_dbg(dev, "Didn't find host pnor flash node\n");
> +               return -ENXIO;
>         } else {
>                 rc = of_address_to_resource(node, 1, &resm);
>                 of_node_put(node);
> --
> 2.20.0
>
Vijay Khemka June 21, 2019, 4:53 p.m. UTC | #2
´╗┐On 6/20/19, 1:29 AM, "Joel Stanley" <joel@jms.id.au> wrote:

    On Wed, 19 Jun 2019 at 12:56, Arnd Bergmann <arnd@arndb.de> wrote:
    >
    > gcc warns that a mising "flash" phandle node leads to undefined
    > behavior later:
    >
    > drivers/soc/aspeed/aspeed-lpc-ctrl.c: In function 'aspeed_lpc_ctrl_probe':
    > drivers/soc/aspeed/aspeed-lpc-ctrl.c:201:18: error: '*((void *)&resm+8)' may be used uninitialized in this function [-Werror=maybe-uninitialized]
    >
    > The device cannot work without this node, so just error out here.
    >
    > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
    
    Thanks Arnd. This looks like it applies on top of Vijay's recent patch?
    
    The intent of that change was to make the driver usable for systems
    that do not want to depend on the flash phandle. I think the fix we
    want looks like this:
    
    --- a/drivers/soc/aspeed/aspeed-lpc-ctrl.c
    +++ b/drivers/soc/aspeed/aspeed-lpc-ctrl.c
    @@ -224,10 +224,11 @@ static int aspeed_lpc_ctrl_probe(struct
    platform_device *pdev)
                            dev_err(dev, "Couldn't address to resource for
    flash\n");
                            return rc;
                    }
    +
    +               lpc_ctrl->pnor_size = resource_size(&resm);
    +               lpc_ctrl->pnor_base = resm.start;
            }
    
    -       lpc_ctrl->pnor_size = resource_size(&resm);
    -       lpc_ctrl->pnor_base = resm.start;
    
    
    Vijay, do you agree?
Yes Joel. Thanks for this.
    
    Cheers,
    
    Joel
    
    > ---
    >  drivers/soc/aspeed/aspeed-lpc-ctrl.c | 1 +
    >  1 file changed, 1 insertion(+)
    >
    > diff --git a/drivers/soc/aspeed/aspeed-lpc-ctrl.c b/drivers/soc/aspeed/aspeed-lpc-ctrl.c
    > index 239520bb207e..81109d22af6a 100644
    > --- a/drivers/soc/aspeed/aspeed-lpc-ctrl.c
    > +++ b/drivers/soc/aspeed/aspeed-lpc-ctrl.c
    > @@ -212,6 +212,7 @@ static int aspeed_lpc_ctrl_probe(struct platform_device *pdev)
    >         node = of_parse_phandle(dev->of_node, "flash", 0);
    >         if (!node) {
    >                 dev_dbg(dev, "Didn't find host pnor flash node\n");
    > +               return -ENXIO;
    >         } else {
    >                 rc = of_address_to_resource(node, 1, &resm);
    >                 of_node_put(node);
    > --
    > 2.20.0
    >

Patch
diff mbox series

diff --git a/drivers/soc/aspeed/aspeed-lpc-ctrl.c b/drivers/soc/aspeed/aspeed-lpc-ctrl.c
index 239520bb207e..81109d22af6a 100644
--- a/drivers/soc/aspeed/aspeed-lpc-ctrl.c
+++ b/drivers/soc/aspeed/aspeed-lpc-ctrl.c
@@ -212,6 +212,7 @@  static int aspeed_lpc_ctrl_probe(struct platform_device *pdev)
 	node = of_parse_phandle(dev->of_node, "flash", 0);
 	if (!node) {
 		dev_dbg(dev, "Didn't find host pnor flash node\n");
+		return -ENXIO;
 	} else {
 		rc = of_address_to_resource(node, 1, &resm);
 		of_node_put(node);