On Tue, Jun 08, 2021 at 09:39:52AM +0800, yekai(A) wrote:
>
>
> On 2021/6/4 15:51, Greg KH wrote:
> > On Fri, Jun 04, 2021 at 03:46:09PM +0800, Kai Ye wrote:
> > > Add print information necessary if user not enable sva.
> > >
> > > Signed-off-by: Kai Ye <yekai13@xxxxxxxxxx>
> > > ---
> > > drivers/misc/uacce/uacce.c | 11 +++++++++--
> > > 1 file changed, 9 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
> > > index bae18ef0..fe38af8 100644
> > > --- a/drivers/misc/uacce/uacce.c
> > > +++ b/drivers/misc/uacce/uacce.c
> > > @@ -387,15 +387,22 @@ static void uacce_release(struct device *dev)
> > >
> > > static unsigned int uacce_enable_sva(struct device *parent, unsigned int flags)
> > > {
> > > + int ret;
> > > +
> > > if (!(flags & UACCE_DEV_SVA))
> > > return flags;
> > >
> > > flags &= ~UACCE_DEV_SVA;
> > >
> > > - if (iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_IOPF))
> > > + ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_IOPF);
> > > + if (ret) {
> > > + dev_err(parent, "failed to enable IOPF feature! ret = %d\n", ret);
> >
> > Why is this needed? Has this ever happened in real life such that the
> > log message is now required?
> >
> >
> >
> > > return flags;
> > > + }
> > >
> > > - if (iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA)) {
> > > + ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA);
> > > + if (ret) {
> > > + dev_err(parent, "failed to enable SVA feature! ret = %d\n", ret);
> >
> > Same here, does this happen in real systems?
> >
> > thanks,
> >
> > greg k-h
> > .
> >
> In a other debug version, the SVA feature failed to be enabled, and no
> related information was printed. we don't know the cause of the problem.
> Finally, Although, it's not the problem here. but we find that the sva
> enable function doesn't have debug information. Therefore, it is
> inconvenient to locate the fault.
> so i think the log message is required.
Ok, can you resend with the changes that Joe suggested to make this even
easier to use?
thanks,
greg k-h
