| Message ID | 493a4f80-677c-b213-d13a-e922b28c38e0@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Mon, Jan 08, 2018 at 07:18:59PM +0530, Vignesh R wrote: > > > On Thursday 04 January 2018 09:42 PM, Lorenzo Pieralisi wrote: > > On Thu, Jan 04, 2018 at 07:04:30PM +0530, Kishon Vijay Abraham I wrote: > >> Hi, > >> > >> On Thursday 04 January 2018 11:38 AM, Kishon Vijay Abraham I wrote: > >>> > >>> > >>> On Friday 29 December 2017 05:11 PM, Vignesh R wrote: > >>>> Legacy INTD IRQ handling is broken on dra7xx due to fact that driver > >>>> uses hwirq in range of 1-4 for INTA, INTD whereas IRQ domain is of size > >>>> 4 which is numbered 0-3. Therefore when INTD IRQ line is used with > >>>> pci-dra7xx driver following warning is seen: > >>>> > >>>> WARNING: CPU: 0 PID: 1 at kernel/irq/irqdomain.c:342 irq_domain_associate+0x12c/0x1c4 > >>>> error: hwirq 0x4 is too large for dummy > >>>> > >>>> Fix this by using pci_irqd_intx_xlate() helper to translate the INTx 1-4 > >>>> range into the 0-3 as done in other PCIe drivers. > >>>> > >>>> Suggested-by: Bjorn Helgaas <bhelgaas@google.com> > >>>> Reported-by: Chris Welch <Chris.Welch@viavisolutions.com> > >>>> Signed-off-by: Vignesh R <vigneshr@ti.com> > >>> > >>> Acked-by: Kishon Vijay Abraham I <kishon@ti.com> > >>>> --- > >>>> drivers/pci/dwc/pci-dra7xx.c | 3 ++- > >>>> 1 file changed, 2 insertions(+), 1 deletion(-) > >>>> > >>>> diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c > >>>> index 58aed0896468..892f93910012 100644 > >>>> --- a/drivers/pci/dwc/pci-dra7xx.c > >>>> +++ b/drivers/pci/dwc/pci-dra7xx.c > >>>> @@ -226,6 +226,7 @@ static int dra7xx_pcie_intx_map(struct irq_domain *domain, unsigned int irq, > >>>> > >>>> static const struct irq_domain_ops intx_domain_ops = { > >>>> .map = dra7xx_pcie_intx_map, > >>>> + .xlate = pci_irqd_intx_xlate, > >> > >> Looking at this again, I think the mapping should be done in device tree using > >> the interrupt-map property. > >> > >> Lorenzo, can you hold merging this patch till we verify using the dt approach? > > > > Yes and I agree that's a DT mapping bug. > > I did some testing by changing interrupt-map property of PCIe node as as > below: > diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi > index 261b5deb2456..2b1a2c5303bb 100644 > --- a/arch/arm/boot/dts/dra7.dtsi > +++ b/arch/arm/boot/dts/dra7.dtsi > @@ -332,10 +332,10 @@ > phys = <&pcie1_phy>; > phy-names = "pcie-phy0"; > interrupt-map-mask = <0 0 0 7>; > - interrupt-map = <0 0 0 1 &pcie1_intc 1>, > - <0 0 0 2 &pcie1_intc 2>, > - <0 0 0 3 &pcie1_intc 3>, > - <0 0 0 4 &pcie1_intc 4>; > + interrupt-map = <0 0 0 1 &pcie1_intc 0>, > + <0 0 0 2 &pcie1_intc 1>, > + <0 0 0 3 &pcie1_intc 2>, > + <0 0 0 4 &pcie1_intc 3>; > > > Although this eliminates need for xlate, we still need driver change to > call the correct handler with above change: > > static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp) > @@ -269,7 +270,7 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int > irq, void *arg) > case INTC: > case INTD: > generic_handle_irq(irq_find_mapping(dra7xx->irq_domain, > - ffs(reg))); > + ffs(reg) - 1)); > break; > } > > > If we merge the driver change then the DT backward compatibility is > broken. Right now INTA/B/C keep working even with buggy interrupt-map > settings. But, if we fix interrupt-map and merge above driver change, > then we will be *breaking* DT backward compatibility and INTA/B/C will > no longer work with older DTs. > Therefore, IMO, this patch should be merged in order to keep DT backward > compatibility and live with wrong DT representation. Yes, this is a mess. I am not fond at all of this fix but I will end up merging it for the same reasons you provided - I can't break backward DT compatibility. Lorenzo
diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi index 261b5deb2456..2b1a2c5303bb 100644 --- a/arch/arm/boot/dts/dra7.dtsi +++ b/arch/arm/boot/dts/dra7.dtsi @@ -332,10 +332,10 @@ phys = <&pcie1_phy>; phy-names = "pcie-phy0"; interrupt-map-mask = <0 0 0 7>; - interrupt-map = <0 0 0 1 &pcie1_intc 1>, - <0 0 0 2 &pcie1_intc 2>, - <0 0 0 3 &pcie1_intc 3>, - <0 0 0 4 &pcie1_intc 4>; + interrupt-map = <0 0 0 1 &pcie1_intc 0>, + <0 0 0 2 &pcie1_intc 1>, + <0 0 0 3 &pcie1_intc 2>, + <0 0 0 4 &pcie1_intc 3>; Although this eliminates need for xlate, we still need driver change to