From: Greg KH <gregkh@linuxfoundation.org>
To: "yekai(A)" <yekai13@huawei.com>
Cc: linux-accelerators@lists.ozlabs.org,
linux-kernel@vger.kernel.org, linuxarm@huawei.com,
zhangfei.gao@linaro.org, wangzhou1@hisilicon.com
Subject: Re: [PATCH] uacce: add print information if not enable sva
Date: Wed, 9 Jun 2021 11:52:34 +0200 [thread overview]
Message-ID: <YMCPYmjHnn8S8soC@kroah.com> (raw)
In-Reply-To: <3f1590c4-b9f1-18f5-370a-57d9707f38a0@huawei.com>
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@huawei.com>
> > > ---
> > > 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
next prev parent reply other threads:[~2021-06-09 9:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-04 7:46 [PATCH] uacce: add print information if not enable sva Kai Ye
2021-06-04 7:51 ` Greg KH
2021-06-08 1:39 ` yekai(A)
2021-06-09 9:52 ` Greg KH [this message]
2021-06-04 7:57 ` Joe Perches
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