| Message ID | 1621213953-54030-1-git-send-email-tiantao6@hisilicon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Lorenzo Pieralisi |
| Headers | show |
| Series | [v2] PCI: tegra: move to use request_irq by IRQF_NO_AUTOEN flag | expand |
Thanks for the patch. Reviewed-by: Vidya Sagar <vidyas@nvidia.com> - Vidya Sagar On 5/17/2021 6:42 AM, Tian Tao wrote: > External email: Use caution opening links or attachments > > > request_irq() after setting IRQ_NOAUTOEN as below > irq_set_status_flags(irq, IRQ_NOAUTOEN); > request_irq(dev, irq...); > can be replaced by request_irq() with IRQF_NO_AUTOEN flag. > > this change is just to simplify the code, no actual functional changes. > > Signed-off-by: Tian Tao <tiantao6@hisilicon.com> > --- > > v2: update the commit message. > --- > drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c > index bafd2c6..7349926 100644 > --- a/drivers/pci/controller/dwc/pcie-tegra194.c > +++ b/drivers/pci/controller/dwc/pcie-tegra194.c > @@ -2021,14 +2021,13 @@ static int tegra_pcie_config_ep(struct tegra_pcie_dw *pcie, > return -ENOMEM; > } > > - irq_set_status_flags(pcie->pex_rst_irq, IRQ_NOAUTOEN); > - > pcie->ep_state = EP_STATE_DISABLED; > > ret = devm_request_threaded_irq(dev, pcie->pex_rst_irq, NULL, > tegra_pcie_ep_pex_rst_irq, > IRQF_TRIGGER_RISING | > - IRQF_TRIGGER_FALLING | IRQF_ONESHOT, > + IRQF_TRIGGER_FALLING | > + IRQF_ONESHOT | IRQF_NO_AUTOEN > name, (void *)pcie); > if (ret < 0) { > dev_err(dev, "Failed to request IRQ for PERST: %d\n", ret); > -- > 2.7.4 >
I want to re-examine this patch. I don't see any references in the kernel where IRQ_NOAUTOEN is passed directly in request_irq APIs. It is always set explicitly through irq_set_status_flags() *before* calling request_irq APIs. I don't see any comment in the header file either that says something like it should always be set before requesting the irq. Lorenzo/Bjorn, could you please throw some light on what is correct thing to do here? Thanks, Vidya Sagar On 5/17/2021 3:47 PM, Vidya Sagar wrote: > Thanks for the patch. > > Reviewed-by: Vidya Sagar <vidyas@nvidia.com> > > - Vidya Sagar > > On 5/17/2021 6:42 AM, Tian Tao wrote: >> External email: Use caution opening links or attachments >> >> >> request_irq() after setting IRQ_NOAUTOEN as below >> irq_set_status_flags(irq, IRQ_NOAUTOEN); >> request_irq(dev, irq...); >> can be replaced by request_irq() with IRQF_NO_AUTOEN flag. >> >> this change is just to simplify the code, no actual functional changes. >> >> Signed-off-by: Tian Tao <tiantao6@hisilicon.com> >> --- >> >> v2: update the commit message. >> --- >> drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- >> 1 file changed, 2 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c >> b/drivers/pci/controller/dwc/pcie-tegra194.c >> index bafd2c6..7349926 100644 >> --- a/drivers/pci/controller/dwc/pcie-tegra194.c >> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c >> @@ -2021,14 +2021,13 @@ static int tegra_pcie_config_ep(struct >> tegra_pcie_dw *pcie, >> return -ENOMEM; >> } >> >> - irq_set_status_flags(pcie->pex_rst_irq, IRQ_NOAUTOEN); >> - >> pcie->ep_state = EP_STATE_DISABLED; >> >> ret = devm_request_threaded_irq(dev, pcie->pex_rst_irq, NULL, >> tegra_pcie_ep_pex_rst_irq, >> IRQF_TRIGGER_RISING | >> - IRQF_TRIGGER_FALLING | >> IRQF_ONESHOT, >> + IRQF_TRIGGER_FALLING | >> + IRQF_ONESHOT | IRQF_NO_AUTOEN >> name, (void *)pcie); >> if (ret < 0) { >> dev_err(dev, "Failed to request IRQ for PERST: %d\n", >> ret); >> -- >> 2.7.4 >>
[+Marc, Thomas] thread: https://lore.kernel.org/linux-pci/1621213953-54030-1-git-send-email-tiantao6@hisilicon.com On Mon, May 31, 2021 at 03:32:33PM +0530, Vidya Sagar wrote: > I want to re-examine this patch. > I don't see any references in the kernel where IRQ_NOAUTOEN is passed > directly in request_irq APIs. AFAICS there are many references, not sure what you actually checked. > It is always set explicitly through irq_set_status_flags() *before* > calling request_irq APIs. I don't see any comment in the header file > either that says something like it should always be set before > requesting the irq. Lorenzo/Bjorn, could you please throw some light > on what is correct thing to do here? To be honest I don't know. Certainly Marc and Thomas know if they have a minute to chime in. Lorenzo > Thanks, > Vidya Sagar > > > On 5/17/2021 3:47 PM, Vidya Sagar wrote: > > Thanks for the patch. > > > > Reviewed-by: Vidya Sagar <vidyas@nvidia.com> > > > > - Vidya Sagar > > > > On 5/17/2021 6:42 AM, Tian Tao wrote: > > > External email: Use caution opening links or attachments > > > > > > > > > request_irq() after setting IRQ_NOAUTOEN as below > > > irq_set_status_flags(irq, IRQ_NOAUTOEN); > > > request_irq(dev, irq...); > > > can be replaced by request_irq() with IRQF_NO_AUTOEN flag. > > > > > > this change is just to simplify the code, no actual functional changes. > > > > > > Signed-off-by: Tian Tao <tiantao6@hisilicon.com> > > > --- > > > > > > v2: update the commit message. > > > --- > > > drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- > > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c > > > b/drivers/pci/controller/dwc/pcie-tegra194.c > > > index bafd2c6..7349926 100644 > > > --- a/drivers/pci/controller/dwc/pcie-tegra194.c > > > +++ b/drivers/pci/controller/dwc/pcie-tegra194.c > > > @@ -2021,14 +2021,13 @@ static int tegra_pcie_config_ep(struct > > > tegra_pcie_dw *pcie, > > > return -ENOMEM; > > > } > > > > > > - irq_set_status_flags(pcie->pex_rst_irq, IRQ_NOAUTOEN); > > > - > > > pcie->ep_state = EP_STATE_DISABLED; > > > > > > ret = devm_request_threaded_irq(dev, pcie->pex_rst_irq, NULL, > > > tegra_pcie_ep_pex_rst_irq, > > > IRQF_TRIGGER_RISING | > > > - IRQF_TRIGGER_FALLING | > > > IRQF_ONESHOT, > > > + IRQF_TRIGGER_FALLING | > > > + IRQF_ONESHOT | IRQF_NO_AUTOEN > > > name, (void *)pcie); > > > if (ret < 0) { > > > dev_err(dev, "Failed to request IRQ for PERST: > > > %d\n", ret); > > > -- > > > 2.7.4 > > >
On Wed, Jun 23, 2021 at 10:45:19AM +0100, Lorenzo Pieralisi wrote: > [+Marc, Thomas] > > thread: https://lore.kernel.org/linux-pci/1621213953-54030-1-git-send-email-tiantao6@hisilicon.com > > On Mon, May 31, 2021 at 03:32:33PM +0530, Vidya Sagar wrote: > > I want to re-examine this patch. > > I don't see any references in the kernel where IRQ_NOAUTOEN is passed > > directly in request_irq APIs. > > AFAICS there are many references, not sure what you actually checked. > > > It is always set explicitly through irq_set_status_flags() *before* > > calling request_irq APIs. I don't see any comment in the header file > > either that says something like it should always be set before > > requesting the irq. Lorenzo/Bjorn, could you please throw some light > > on what is correct thing to do here? > > To be honest I don't know. Certainly Marc and Thomas know if they have > a minute to chime in. I don't know either. If this *is* the right thing to do it needs a much better commit log because this is not merely a simplification that can be verified with a couple minutes of code reading. This is the only use of IRQ_NOAUTOEN in drivers/pci/, which itself raises the question of why we need it. Also, please update the subject line to s/tegra/tegra194/ and start with a capital letter to match convention. > > On 5/17/2021 3:47 PM, Vidya Sagar wrote: > > > Thanks for the patch. > > > > > > Reviewed-by: Vidya Sagar <vidyas@nvidia.com> > > > > > > - Vidya Sagar > > > > > > On 5/17/2021 6:42 AM, Tian Tao wrote: > > > > External email: Use caution opening links or attachments > > > > > > > > > > > > request_irq() after setting IRQ_NOAUTOEN as below > > > > irq_set_status_flags(irq, IRQ_NOAUTOEN); > > > > request_irq(dev, irq...); > > > > can be replaced by request_irq() with IRQF_NO_AUTOEN flag. > > > > > > > > this change is just to simplify the code, no actual functional changes. > > > > > > > > Signed-off-by: Tian Tao <tiantao6@hisilicon.com> > > > > --- > > > > > > > > v2: update the commit message. > > > > --- > > > > drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- > > > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c > > > > b/drivers/pci/controller/dwc/pcie-tegra194.c > > > > index bafd2c6..7349926 100644 > > > > --- a/drivers/pci/controller/dwc/pcie-tegra194.c > > > > +++ b/drivers/pci/controller/dwc/pcie-tegra194.c > > > > @@ -2021,14 +2021,13 @@ static int tegra_pcie_config_ep(struct > > > > tegra_pcie_dw *pcie, > > > > return -ENOMEM; > > > > } > > > > > > > > - irq_set_status_flags(pcie->pex_rst_irq, IRQ_NOAUTOEN); > > > > - > > > > pcie->ep_state = EP_STATE_DISABLED; > > > > > > > > ret = devm_request_threaded_irq(dev, pcie->pex_rst_irq, NULL, > > > > tegra_pcie_ep_pex_rst_irq, > > > > IRQF_TRIGGER_RISING | > > > > - IRQF_TRIGGER_FALLING | > > > > IRQF_ONESHOT, > > > > + IRQF_TRIGGER_FALLING | > > > > + IRQF_ONESHOT | IRQF_NO_AUTOEN > > > > name, (void *)pcie); > > > > if (ret < 0) { > > > > dev_err(dev, "Failed to request IRQ for PERST: > > > > %d\n", ret); > > > > -- > > > > 2.7.4 > > > >
On Mon, May 31, 2021 at 03:32:33PM +0530, Vidya Sagar wrote: > I want to re-examine this patch. > I don't see any references in the kernel where IRQ_NOAUTOEN is passed > directly in request_irq APIs. It is always set explicitly through > irq_set_status_flags() *before* calling request_irq APIs. [...] The request_irq() flag is called IRQF_NO_AUTOEN. As far as I can read the cod, it does seem equivalent to changing irq_settings. I'm not sure why we have two methods to do this in the kernel, though. Hope that helps. Best Regards Michał Mirosław
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index bafd2c6..7349926 100644 --- a/drivers/pci/controller/dwc/pcie-tegra194.c +++ b/drivers/pci/controller/dwc/pcie-tegra194.c @@ -2021,14 +2021,13 @@ static int tegra_pcie_config_ep(struct tegra_pcie_dw *pcie, return -ENOMEM; } - irq_set_status_flags(pcie->pex_rst_irq, IRQ_NOAUTOEN); - pcie->ep_state = EP_STATE_DISABLED; ret = devm_request_threaded_irq(dev, pcie->pex_rst_irq, NULL, tegra_pcie_ep_pex_rst_irq, IRQF_TRIGGER_RISING | - IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + IRQF_TRIGGER_FALLING | + IRQF_ONESHOT | IRQF_NO_AUTOEN name, (void *)pcie); if (ret < 0) { dev_err(dev, "Failed to request IRQ for PERST: %d\n", ret);
request_irq() after setting IRQ_NOAUTOEN as below irq_set_status_flags(irq, IRQ_NOAUTOEN); request_irq(dev, irq...); can be replaced by request_irq() with IRQF_NO_AUTOEN flag. this change is just to simplify the code, no actual functional changes. Signed-off-by: Tian Tao <tiantao6@hisilicon.com> --- v2: update the commit message. --- drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)