On 11/01/2013 03:08 PM, scame...@beardog.cce.hp.com wrote:
> On Fri, Nov 01, 2013 at 06:31:10AM -0700, Andrew Morton wrote:
>> On Fri, 01 Nov 2013 14:06:45 +0100 Tomas Henzl <the...@redhat.com> wrote:
>>
>>> The problem in kernel is that the error handling in local_pci_probe
>>> and in __pci_device_probe is different for ret values > 0,
>>> so we should fix it somewhere so it is in sync.
>>> The documentation states that the probe function should return zero on
>>> success
>>> so what about this -
>>>
>>> This would bring the handling to sync
>>> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
>>> index 98f7b9b..200a071 100644
>>> --- a/drivers/pci/pci-driver.c
>>> +++ b/drivers/pci/pci-driver.c
>>> @@ -317,8 +317,6 @@ __pci_device_probe(struct pci_driver *drv, struct
>>> pci_dev *pci_dev)
>>> id = pci_match_device(drv, pci_dev);
>>> if (id)
>>> error = pci_call_probe(drv, pci_dev, id);
>>> - if (error >= 0)
>>> - error = 0;
>>> }
>>> return error;
>>> }
>> ah, there it is.
>>
>> This change would turn semi-kaput drivers into kaput-kaput drivers. It
>> would be better to add a runtime warning here so those drivers get
>> fixed. Such a warning would need to reliably identify the offending
>> probe function so a simple WARN_ON() wouldn't be sufficient.
>>
> FWIW, I just booted up with the following change:
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 98f7b9b..ef71bb5 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -264,9 +264,16 @@ static long local_pci_probe(void *_ddi)
> pm_runtime_get_sync(dev);
> pci_dev->driver = pci_drv;
> rc = pci_drv->probe(pci_dev, ddi->id);
> - if (rc) {
> + if (rc < 0) {
> pci_dev->driver = NULL;
> pm_runtime_put_sync(dev);
> + } else {
> + if (rc > 0) {
> + dev_warn(dev,
> + "Driver probe function returned %d, greater
> than 0\n", rc);
> + rc = 0;
> +
> + }
> }
> return rc;
> }
>
>
> And,
>
> [scameron@localhost linux-3.12-rc6]$ dmesg | grep 'Driver probe'
> [scameron@localhost linux-3.12-rc6]$
>
> Not that it means all that much since I don't have hardware for
> the majority of drivers, obviously.
>
> I think the above should make drivers with probe functions
> returning > 0 "work" again, but with a warning.
>
> The question would be, are there drivers which return > 0 and
> by this value intend to convey that the probe function has failed?
I think that this is unlikely and the patch is fine, but I can't speak for the
drivers..
Please repost your patch so it gets more attention than in this thread.
>
> -- steve
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
