[PATCH v2 0/2] pci-dra7xx: Fix legacy IRQ handling

[PATCH v2 0/2] pci-dra7xx: Fix legacy IRQ handling

[Vignesh R]

This series fixes couple of issues wrt PCIe legacy IRQ handling on
dra7xx platforms.

Tested on DRA74 EVM.

Changes in v2:
 * Drop patches related to errata i870 handling. That will be posted
   separately later.
 * Split INTD IRQ handling into separate patch.

v1: https://lkml.org/lkml/2017/12/1/59

Vignesh R (2):
  PCI: dra7xx: Fix legacy INTD IRQ handling
  PCI: dra7xx: Iterate over INTx status bits

 drivers/pci/dwc/pci-dra7xx.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

-- 
2.15.1

[PATCH v2 1/2] PCI: dra7xx: Fix legacy INTD IRQ handling

[Vignesh R]

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>
---
 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,
 };
 
 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;
 	}
 
-- 
2.15.1

Re: [PATCH v2 1/2] PCI: dra7xx: Fix legacy INTD IRQ handling

[Kishon Vijay Abraham I]

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,
>  };
>  
>  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;
>  	}
>  
> 

Re: [PATCH v2 1/2] PCI: dra7xx: Fix legacy INTD IRQ handling

[Kishon Vijay Abraham I]

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?

Thanks
Kishon

Re: [PATCH v2 1/2] PCI: dra7xx: Fix legacy INTD IRQ handling

[Lorenzo Pieralisi]

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.

Lorenzo

Re: [PATCH v2 1/2] PCI: dra7xx: Fix legacy INTD IRQ handling

[Vignesh R]

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.


-- 
Regards
Vignesh

Re: [PATCH v2 1/2] PCI: dra7xx: Fix legacy INTD IRQ handling

[Lorenzo Pieralisi]

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

Re: [PATCH v2 1/2] PCI: dra7xx: Fix legacy INTD IRQ handling

[Lorenzo Pieralisi]

On Fri, Dec 29, 2017 at 05:11:30PM +0530, 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>
> ---
>  drivers/pci/dwc/pci-dra7xx.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Applied to pci/dwc for v4.16, thanks.

Lorenzo

> 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,
>  };
>  
>  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;
>  	}
>  
> -- 
> 2.15.1
> 

[PATCH v2 2/2] PCI: dra7xx: Iterate over INTx status bits

[Vignesh R]

It is possible that more than one legacy IRQ may be set at the same
time, therefore iterate and handle all the pending INTx interrupts
before clearing the status and exiting the IRQ handler. Otherwise, some
interrupts would be lost.

Signed-off-by: Vignesh R <vigneshr@ti.com>
---
 drivers/pci/dwc/pci-dra7xx.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index 892f93910012..48c6ae535847 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -257,7 +257,8 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
 	struct dra7xx_pcie *dra7xx = arg;
 	struct dw_pcie *pci = dra7xx->pci;
 	struct pcie_port *pp = &pci->pp;
-	u32 reg;
+	unsigned long reg;
+	u32 virq, bit;
 
 	reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI);
 
@@ -269,8 +270,11 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
 	case INTB:
 	case INTC:
 	case INTD:
-		generic_handle_irq(irq_find_mapping(dra7xx->irq_domain,
-						    ffs(reg) - 1));
+		for_each_set_bit(bit, &reg, PCI_NUM_INTX) {
+			virq = irq_find_mapping(dra7xx->irq_domain, bit);
+			if (virq)
+				generic_handle_irq(virq);
+		}
 		break;
 	}
 
-- 
2.15.1

Re: [PATCH v2 2/2] PCI: dra7xx: Iterate over INTx status bits

[Lorenzo Pieralisi]

On Fri, Dec 29, 2017 at 05:11:31PM +0530, Vignesh R wrote:
> It is possible that more than one legacy IRQ may be set at the same
> time, therefore iterate and handle all the pending INTx interrupts
> before clearing the status and exiting the IRQ handler. Otherwise, some
> interrupts would be lost.
> 
> Signed-off-by: Vignesh R <vigneshr@ti.com>
> ---
>  drivers/pci/dwc/pci-dra7xx.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
> index 892f93910012..48c6ae535847 100644
> --- a/drivers/pci/dwc/pci-dra7xx.c
> +++ b/drivers/pci/dwc/pci-dra7xx.c
> @@ -257,7 +257,8 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
>  	struct dra7xx_pcie *dra7xx = arg;
>  	struct dw_pcie *pci = dra7xx->pci;
>  	struct pcie_port *pp = &pci->pp;
> -	u32 reg;
> +	unsigned long reg;
> +	u32 virq, bit;
>  
>  	reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI);
>  
> @@ -269,8 +270,11 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
>  	case INTB:
>  	case INTC:
>  	case INTD:
> -		generic_handle_irq(irq_find_mapping(dra7xx->irq_domain,
> -						    ffs(reg) - 1));
> +		for_each_set_bit(bit, &reg, PCI_NUM_INTX) {
> +			virq = irq_find_mapping(dra7xx->irq_domain, bit);
> +			if (virq)
> +				generic_handle_irq(virq);
> +		}
>  		break;
>  	}

It is not strictly related to this patch but why MSI and INTX are
handled as mutually exclusive in dra7xx_pcie_msi_irq_handler() ?

Lorenzo

Re: [PATCH v2 2/2] PCI: dra7xx: Iterate over INTx status bits

[Vignesh R]

On Tuesday 02 January 2018 09:17 PM, Lorenzo Pieralisi wrote:
> On Fri, Dec 29, 2017 at 05:11:31PM +0530, Vignesh R wrote:
>> It is possible that more than one legacy IRQ may be set at the same
>> time, therefore iterate and handle all the pending INTx interrupts
>> before clearing the status and exiting the IRQ handler. Otherwise, some
>> interrupts would be lost.
>> 
>> Signed-off-by: Vignesh R <vigneshr@ti.com>
>> ---
>>  drivers/pci/dwc/pci-dra7xx.c | 10 +++++++---
>>  1 file changed, 7 insertions(+), 3 deletions(-)
>> 
>> diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
>> index 892f93910012..48c6ae535847 100644
>> --- a/drivers/pci/dwc/pci-dra7xx.c
>> +++ b/drivers/pci/dwc/pci-dra7xx.c
>> @@ -257,7 +257,8 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
>>        struct dra7xx_pcie *dra7xx = arg;
>>        struct dw_pcie *pci = dra7xx->pci;
>>        struct pcie_port *pp = &pci->pp;
>> -     u32 reg;
>> +     unsigned long reg;
>> +     u32 virq, bit;
>>  
>>        reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI);
>>  
>> @@ -269,8 +270,11 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
>>        case INTB:
>>        case INTC:
>>        case INTD:
>> -             generic_handle_irq(irq_find_mapping(dra7xx->irq_domain,
>> -                                                 ffs(reg) - 1));
>> +             for_each_set_bit(bit, &reg, PCI_NUM_INTX) {
>> +                     virq = irq_find_mapping(dra7xx->irq_domain, bit);
>> +                     if (virq)
>> +                             generic_handle_irq(virq);
>> +             }
>>                break;
>>        }
> 
> It is not strictly related to this patch but why MSI and INTX are
> handled as mutually exclusive in dra7xx_pcie_msi_irq_handler() ?

I think the driver previously assumed MSI and legacy IRQs are exclusive
of each other, which is not true. Will try to fix this along with couple
of other fixes that I have for MSI IRQ handling.


-- 
Regards
Vignesh

Re: [PATCH v2 2/2] PCI: dra7xx: Iterate over INTx status bits

[Kishon Vijay Abraham I]

On Friday 29 December 2017 05:11 PM, Vignesh R wrote:
> It is possible that more than one legacy IRQ may be set at the same
> time, therefore iterate and handle all the pending INTx interrupts
> before clearing the status and exiting the IRQ handler. Otherwise, some
> interrupts would be lost.
> 
> Signed-off-by: Vignesh R <vigneshr@ti.com>

Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  drivers/pci/dwc/pci-dra7xx.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
> index 892f93910012..48c6ae535847 100644
> --- a/drivers/pci/dwc/pci-dra7xx.c
> +++ b/drivers/pci/dwc/pci-dra7xx.c
> @@ -257,7 +257,8 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
>  	struct dra7xx_pcie *dra7xx = arg;
>  	struct dw_pcie *pci = dra7xx->pci;
>  	struct pcie_port *pp = &pci->pp;
> -	u32 reg;
> +	unsigned long reg;
> +	u32 virq, bit;
>  
>  	reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI);
>  
> @@ -269,8 +270,11 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
>  	case INTB:
>  	case INTC:
>  	case INTD:
> -		generic_handle_irq(irq_find_mapping(dra7xx->irq_domain,
> -						    ffs(reg) - 1));
> +		for_each_set_bit(bit, &reg, PCI_NUM_INTX) {
> +			virq = irq_find_mapping(dra7xx->irq_domain, bit);
> +			if (virq)
> +				generic_handle_irq(virq);
> +		}
>  		break;
>  	}
>  
> 

Re: [PATCH v2 2/2] PCI: dra7xx: Iterate over INTx status bits

[Lorenzo Pieralisi]

On Fri, Dec 29, 2017 at 05:11:31PM +0530, Vignesh R wrote:
> It is possible that more than one legacy IRQ may be set at the same
> time, therefore iterate and handle all the pending INTx interrupts
> before clearing the status and exiting the IRQ handler. Otherwise, some
> interrupts would be lost.
> 
> Signed-off-by: Vignesh R <vigneshr@ti.com>
> ---
>  drivers/pci/dwc/pci-dra7xx.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)

Applied to pci/dwc for v4.16, thanks.

Lorenzo

> diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
> index 892f93910012..48c6ae535847 100644
> --- a/drivers/pci/dwc/pci-dra7xx.c
> +++ b/drivers/pci/dwc/pci-dra7xx.c
> @@ -257,7 +257,8 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
>  	struct dra7xx_pcie *dra7xx = arg;
>  	struct dw_pcie *pci = dra7xx->pci;
>  	struct pcie_port *pp = &pci->pp;
> -	u32 reg;
> +	unsigned long reg;
> +	u32 virq, bit;
>  
>  	reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI);
>  
> @@ -269,8 +270,11 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
>  	case INTB:
>  	case INTC:
>  	case INTD:
> -		generic_handle_irq(irq_find_mapping(dra7xx->irq_domain,
> -						    ffs(reg) - 1));
> +		for_each_set_bit(bit, &reg, PCI_NUM_INTX) {
> +			virq = irq_find_mapping(dra7xx->irq_domain, bit);
> +			if (virq)
> +				generic_handle_irq(virq);
> +		}
>  		break;
>  	}
>  
> -- 
> 2.15.1
>