On Fri, Jun 02, 2023 at 08:18:58AM +0900, Damien Le Moal wrote:
> On 6/1/23 23:57, Manivannan Sadhasivam wrote:
> > When the EPC is started or stopped multiple times from configfs, just emit
> > a once time warning and return. There is no need to call the EPC start/stop
> > functions in those cases.
> >
> > Reviewed-by: Kishon Vijay Abraham I <kishon@xxxxxxxxxx>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > ---
> > drivers/pci/endpoint/pci-ep-cfs.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
> > index 4b8ac0ac84d5..62c8e09c59f4 100644
> > --- a/drivers/pci/endpoint/pci-ep-cfs.c
> > +++ b/drivers/pci/endpoint/pci-ep-cfs.c
> > @@ -178,6 +178,9 @@ static ssize_t pci_epc_start_store(struct config_item *item, const char *page,
> > if (kstrtobool(page, &start) < 0)
> > return -EINVAL;
> >
> > + if (WARN_ON_ONCE(start == epc_group->start))
> > + return 0;
>
> WARN will dump a backtrace which is fairly scary for the user. This case is
> simply a bad user manipulation of the device, so why not simply add a pr_err()
> (optional) and return -EALREADY ?
>
There EPF core uses WARN_ON_ONCE in other similar places, so thought of sticking
to that pattern. But I agree, WARN_ON_ONCE is not strictly required here. Will
add a error log and return the appropriate error no.
Moreover, will push a patch later to change other instances as well.
- Mani
> > +
> > if (!start) {
> > pci_epc_stop(epc);
> > epc_group->start = 0;
>
> --
> Damien Le Moal
> Western Digital Research
>
--
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