| Message ID | 20230601145718.12204-5-manivannan.sadhasivam@linaro.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add support for MHI Endpoint function driver | expand |
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@kernel.org> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > --- > 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 ? > + > if (!start) { > pci_epc_stop(epc); > epc_group->start = 0;
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@kernel.org> > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > --- > > 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 >
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; + if (!start) { pci_epc_stop(epc); epc_group->start = 0;