Re: [PATCH v2 3/6] vfio: platform: reset: calxedaxgmac: add reset function registration

Arnd Bergmann
2015-10-22T12:09:49Z

On Thursday 22 October 2015 13:54:42 Eric Auger wrote:
> On 10/22/2015 12:13 PM, Arnd Bergmann wrote:
> > On Thursday 22 October 2015 11:41:59 Eric Auger wrote:
> >> This patch adds the reset function registration/unregistration.
> >>
> >> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> >
> > Looks good, except one thing:
> >> @@ -70,6 +69,8 @@ int vfio_platform_calxedaxgmac_reset(struct vfio_platform_device *vdev)
> >> return -ENOMEM;
> >> }
> >>
> >> + pr_info("VFIO reset of %s\n", vdev->name);
> >> +
> >> /* disable IRQ */
> >> writel(0, reg.ioaddr + XGMAC_DMA_INTR_ENA);
> >>
> >
> > This probably slipped in from debugging, please remove it.
> Well actually this is not an oversight but some unappropriate tracing
> attempt I am afraid. I wanted to add a trace useful for the end-user to
> make sure the VFIO reset function was called. Do you forbid that or do
> recommend to use another tracing mechanism/level? In the past I tried
> dynamic tracing but with module loading mechanism I found it not that handy.

If you think it's useful to have in the long run, it should be a separate
patch with a description what it's good for, rather than a side-effect of
an unrelated patch. It just looked to me like it's something you do
while debugging the reset code, rather than while using it.

Implementation-wise, you should use dev_info() instead of pr_info() where
possible, and it probably makes sense to put this into the vfio_platform
driver before calling the reset function, for consistency between the
drivers.

Arnd