Re: [PATCH -next] i2c: Fix missing pci_disable_device() on error in ali1535_setup()

[Samuel Zou]

Hi Jean,

Thanks for your review and detailed explanation.

On 2021/6/8 17:46, Jean Delvare wrote:
> Hi Wei,
>
> On Mon, 07 Jun 2021 11:21:08 +0800, Zou Wei wrote:
> > Fix the missing pci_disable_device() before return
> > from ali1535_setup() in the error handling case.
> >
> > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> > Signed-off-by: Zou Wei <zou_wei@xxxxxxxxxx>
> > ---
> >   drivers/i2c/busses/i2c-ali1535.c | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/i2c/busses/i2c-ali1535.c b/drivers/i2c/busses/i2c-ali1535.c
> > index fb93152..bdbaf79 100644
> > --- a/drivers/i2c/busses/i2c-ali1535.c
> > +++ b/drivers/i2c/busses/i2c-ali1535.c
> > @@ -206,6 +206,7 @@ static int ali1535_setup(struct pci_dev *dev)
> >   exit_free:
> >   	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
> >   exit:
> > +	pci_disable_device(dev);
> >   	return retval;
> >   }
> >   
>
> We don't actually want to disable the PCI device. Maybe it was already
> enabled before the driver was loaded, and maybe the BIOS needs the
> device when the system is being shut down. You'll notice that we do not
> call pci_disable_device(dev) in ali1535_remove(), so there's no reason
> to do it in the error path.
>
> As a matter of fact the i2c-i801 driver, which is used on the same kind
> of hardware, has the following note in its remove function:
>
> 	/*
> 	 * do not call pci_disable_device(dev) since it can cause hard hangs on
> 	 * some systems during power-off (eg. Fujitsu-Siemens Lifebook E8010)
> 	 */
>
> So this is a nack from me, sorry.