| Message ID | 1523365446-31563-1-git-send-email-baijiaju1990@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | Lorenzo Pieralisi |
| Headers | show |
| Series | pci: endpoint: Replace mdelay with usleep_range in pci_epf_test_write | expand |
On Tue, Apr 10, 2018 at 09:04:06PM +0800, Jia-Ju Bai wrote: > pci_epf_test_write() is never called in atomic context. > > The call chain ending up at pci_epf_test_write() is: > [1] pci_epf_test_write() <- pci_epf_test_cmd_handler() > > pci_epf_test_cmd_handler() is set as a parameter of INIT_DELAYED_WORK() > in pci_epf_test_probe(). > This function is not called in atomic context. > > Despite never getting called from atomic context, pci_epf_test_write() > calls mdelay() to busily wait. > This is not necessary and can be replaced with usleep_range() to > avoid busy waiting. > > This is found by a static analysis tool named DCNS written by myself. > And I also manually check it. > > Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> > --- > drivers/pci/endpoint/functions/pci-epf-test.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) I'd request Kishon's ACK on this. Thanks, Lorenzo > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > index f9308c2..2f0642e 100644 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > @@ -237,7 +237,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test) > * wait 1ms inorder for the write to complete. Without this delay L3 > * error in observed in the host system. > */ > - mdelay(1); > + usleep_range(1000, 2000); > > kfree(buf); > > -- > 1.9.1 >
On Friday 04 May 2018 09:59 PM, Lorenzo Pieralisi wrote: > On Tue, Apr 10, 2018 at 09:04:06PM +0800, Jia-Ju Bai wrote: >> pci_epf_test_write() is never called in atomic context. >> >> The call chain ending up at pci_epf_test_write() is: >> [1] pci_epf_test_write() <- pci_epf_test_cmd_handler() >> >> pci_epf_test_cmd_handler() is set as a parameter of INIT_DELAYED_WORK() >> in pci_epf_test_probe(). >> This function is not called in atomic context. >> >> Despite never getting called from atomic context, pci_epf_test_write() >> calls mdelay() to busily wait. >> This is not necessary and can be replaced with usleep_range() to >> avoid busy waiting. >> >> This is found by a static analysis tool named DCNS written by myself. >> And I also manually check it. >> >> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> >> --- >> drivers/pci/endpoint/functions/pci-epf-test.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) > > I'd request Kishon's ACK on this. sorry, missed this before. Acked-by: Kishon Vijay Abraham I <kishon@ti.com> > > Thanks, > Lorenzo > >> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c >> index f9308c2..2f0642e 100644 >> --- a/drivers/pci/endpoint/functions/pci-epf-test.c >> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c >> @@ -237,7 +237,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test) >> * wait 1ms inorder for the write to complete. Without this delay L3 >> * error in observed in the host system. >> */ >> - mdelay(1); >> + usleep_range(1000, 2000); >> >> kfree(buf); >> >> -- >> 1.9.1 >>
On Tue, Apr 10, 2018 at 09:04:06PM +0800, Jia-Ju Bai wrote: > pci_epf_test_write() is never called in atomic context. > > The call chain ending up at pci_epf_test_write() is: > [1] pci_epf_test_write() <- pci_epf_test_cmd_handler() > > pci_epf_test_cmd_handler() is set as a parameter of INIT_DELAYED_WORK() > in pci_epf_test_probe(). > This function is not called in atomic context. > > Despite never getting called from atomic context, pci_epf_test_write() > calls mdelay() to busily wait. > This is not necessary and can be replaced with usleep_range() to > avoid busy waiting. > > This is found by a static analysis tool named DCNS written by myself. > And I also manually check it. > > Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> > --- > drivers/pci/endpoint/functions/pci-epf-test.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Applied to pci/endpoint for v4.18, thanks. Lorenzo > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > index f9308c2..2f0642e 100644 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > @@ -237,7 +237,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test) > * wait 1ms inorder for the write to complete. Without this delay L3 > * error in observed in the host system. > */ > - mdelay(1); > + usleep_range(1000, 2000); > > kfree(buf); > > -- > 1.9.1 >
On Tue, Apr 10, 2018 at 09:04:06PM +0800, Jia-Ju Bai wrote: > pci_epf_test_write() is never called in atomic context. > > The call chain ending up at pci_epf_test_write() is: > [1] pci_epf_test_write() <- pci_epf_test_cmd_handler() > > pci_epf_test_cmd_handler() is set as a parameter of INIT_DELAYED_WORK() > in pci_epf_test_probe(). > This function is not called in atomic context. > > Despite never getting called from atomic context, pci_epf_test_write() > calls mdelay() to busily wait. > This is not necessary and can be replaced with usleep_range() to > avoid busy waiting. > > This is found by a static analysis tool named DCNS written by myself. > And I also manually check it. > > Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> > --- > drivers/pci/endpoint/functions/pci-epf-test.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Applied to pci/endpoint for v4.18, thanks. Lorenzo > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > index f9308c2..2f0642e 100644 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > @@ -237,7 +237,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test) > * wait 1ms inorder for the write to complete. Without this delay L3 > * error in observed in the host system. > */ > - mdelay(1); > + usleep_range(1000, 2000); > > kfree(buf); > > -- > 1.9.1 >
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index f9308c2..2f0642e 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -237,7 +237,7 @@ static int pci_epf_test_write(struct pci_epf_test *epf_test) * wait 1ms inorder for the write to complete. Without this delay L3 * error in observed in the host system. */ - mdelay(1); + usleep_range(1000, 2000); kfree(buf);
pci_epf_test_write() is never called in atomic context. The call chain ending up at pci_epf_test_write() is: [1] pci_epf_test_write() <- pci_epf_test_cmd_handler() pci_epf_test_cmd_handler() is set as a parameter of INIT_DELAYED_WORK() in pci_epf_test_probe(). This function is not called in atomic context. Despite never getting called from atomic context, pci_epf_test_write() calls mdelay() to busily wait. This is not necessary and can be replaced with usleep_range() to avoid busy waiting. This is found by a static analysis tool named DCNS written by myself. And I also manually check it. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/pci/endpoint/functions/pci-epf-test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)