| Message ID | 1415102525-9898-21-git-send-email-jiang.liu@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Nov 04, 2014 at 08:01:54PM +0800, Jiang Liu wrote: > It's arch_setup_msi_irq()/arch_setup_msi_irqs()'s responsibility to call > irq_set_msi_desc() to associate IRQ descriptors and MSI descriptors, > so kill the redundant call of irq_set_msi_desc() for MSIx interrupts > in PCI MSI core. "MSI-X" in English text, "msix" in code. The default arch_setup_msi_irq() in drivers/pci/msi.c doesn't call irq_set_msi_desc(). Does it happen somewhere inside chip->setup_irq()? I don't know how to verify that there are calls in all the places needed. That makes me wonder if the factoring is wrong -- maybe irq_set_msi_desc() could be done in some common place. > Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> > --- > drivers/pci/msi.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c > index afe974600c7d..da181c59394b 100644 > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -685,7 +685,6 @@ static void msix_program_entries(struct pci_dev *dev, > PCI_MSIX_ENTRY_VECTOR_CTRL; > > entries[i].vector = entry->irq; > - irq_set_msi_desc(entry->irq, entry); > entry->masked = readl(entry->mask_base + offset); > msix_mask_irq(entry, 1); > i++; > -- > 1.7.10.4 >
On 2014/11/6 6:45, Bjorn Helgaas wrote: > On Tue, Nov 04, 2014 at 08:01:54PM +0800, Jiang Liu wrote: >> It's arch_setup_msi_irq()/arch_setup_msi_irqs()'s responsibility to call >> irq_set_msi_desc() to associate IRQ descriptors and MSI descriptors, >> so kill the redundant call of irq_set_msi_desc() for MSIx interrupts >> in PCI MSI core. > > "MSI-X" in English text, "msix" in code. > > The default arch_setup_msi_irq() in drivers/pci/msi.c doesn't call > irq_set_msi_desc(). Does it happen somewhere inside chip->setup_irq()? Yes. I also found this. http://www.spinics.net/lists/linux-pci/msg34256.html > > I don't know how to verify that there are calls in all the places needed. > That makes me wonder if the factoring is wrong -- maybe irq_set_msi_desc() > could be done in some common place. In my idea, place the irq_set_msi_desc() in common MSI core is ok, but currently almost all MSI arch code call irq_set_msi_desc() in arch code. So a lot of code need to change. And arch code setup MSI and MSI-X in the same way, so if MSI work happy without irq_set_msi_desc(entry->irq, entry) in common MSI code, MSI-X should be the same. > >> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> >> --- >> drivers/pci/msi.c | 1 - >> 1 file changed, 1 deletion(-) >> >> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c >> index afe974600c7d..da181c59394b 100644 >> --- a/drivers/pci/msi.c >> +++ b/drivers/pci/msi.c >> @@ -685,7 +685,6 @@ static void msix_program_entries(struct pci_dev *dev, >> PCI_MSIX_ENTRY_VECTOR_CTRL; >> >> entries[i].vector = entry->irq; >> - irq_set_msi_desc(entry->irq, entry); >> entry->masked = readl(entry->mask_base + offset); >> msix_mask_irq(entry, 1); >> i++; >> -- >> 1.7.10.4 >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > . >
On Wed, Nov 5, 2014 at 6:32 PM, Yijing Wang <wangyijing@huawei.com> wrote: > On 2014/11/6 6:45, Bjorn Helgaas wrote: >> On Tue, Nov 04, 2014 at 08:01:54PM +0800, Jiang Liu wrote: >>> It's arch_setup_msi_irq()/arch_setup_msi_irqs()'s responsibility to call >>> irq_set_msi_desc() to associate IRQ descriptors and MSI descriptors, >>> so kill the redundant call of irq_set_msi_desc() for MSIx interrupts >>> in PCI MSI core. >> >> "MSI-X" in English text, "msix" in code. >> >> The default arch_setup_msi_irq() in drivers/pci/msi.c doesn't call >> irq_set_msi_desc(). Does it happen somewhere inside chip->setup_irq()? > > Yes. > > I also found this. > http://www.spinics.net/lists/linux-pci/msg34256.html Yes, and I asked the same question then :) It's just impractical to review things like this that make assumptions about lots of code scattered all over the place with no direct linkage to the change. Bjorn
On 2014/11/6 9:32, Yijing Wang wrote: > On 2014/11/6 6:45, Bjorn Helgaas wrote: >> On Tue, Nov 04, 2014 at 08:01:54PM +0800, Jiang Liu wrote: >>> It's arch_setup_msi_irq()/arch_setup_msi_irqs()'s responsibility to call >>> irq_set_msi_desc() to associate IRQ descriptors and MSI descriptors, >>> so kill the redundant call of irq_set_msi_desc() for MSIx interrupts >>> in PCI MSI core. >> >> "MSI-X" in English text, "msix" in code. >> >> The default arch_setup_msi_irq() in drivers/pci/msi.c doesn't call >> irq_set_msi_desc(). Does it happen somewhere inside chip->setup_irq()? > > Yes. > > I also found this. > http://www.spinics.net/lists/linux-pci/msg34256.html > >> >> I don't know how to verify that there are calls in all the places needed. >> That makes me wonder if the factoring is wrong -- maybe irq_set_msi_desc() >> could be done in some common place. > > In my idea, place the irq_set_msi_desc() in common MSI core is ok, but currently almost > all MSI arch code call irq_set_msi_desc() in arch code. So a lot of code need to change. > And arch code setup MSI and MSI-X in the same way, so if MSI work happy without irq_set_msi_desc(entry->irq, entry) > in common MSI code, MSI-X should be the same. Hi Bjorn and Yijing, I originally plan was to move irq_set_msi_desc() into common PCI MSI code. But when implementing this, I found every arch_setup_msi_irq()/arch_setup_msi_irqs() needs to set msidesc->irq, thus need to lock the irq descriptor. So I realized we should rely on arch_setup_msi_irq() to call irq_set_msi_desc():) Regards! Gerry > >> >>> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> >>> --- >>> drivers/pci/msi.c | 1 - >>> 1 file changed, 1 deletion(-) >>> >>> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c >>> index afe974600c7d..da181c59394b 100644 >>> --- a/drivers/pci/msi.c >>> +++ b/drivers/pci/msi.c >>> @@ -685,7 +685,6 @@ static void msix_program_entries(struct pci_dev *dev, >>> PCI_MSIX_ENTRY_VECTOR_CTRL; >>> >>> entries[i].vector = entry->irq; >>> - irq_set_msi_desc(entry->irq, entry); >>> entry->masked = readl(entry->mask_base + offset); >>> msix_mask_irq(entry, 1); >>> i++; >>> -- >>> 1.7.10.4 >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> . >> > >
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index afe974600c7d..da181c59394b 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -685,7 +685,6 @@ static void msix_program_entries(struct pci_dev *dev, PCI_MSIX_ENTRY_VECTOR_CTRL; entries[i].vector = entry->irq; - irq_set_msi_desc(entry->irq, entry); entry->masked = readl(entry->mask_base + offset); msix_mask_irq(entry, 1); i++;
It's arch_setup_msi_irq()/arch_setup_msi_irqs()'s responsibility to call irq_set_msi_desc() to associate IRQ descriptors and MSI descriptors, so kill the redundant call of irq_set_msi_desc() for MSIx interrupts in PCI MSI core. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> --- drivers/pci/msi.c | 1 - 1 file changed, 1 deletion(-)