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@xxxxxx>
>> ---
>>Â drivers/pci/dwc/pci-dra7xx.c | 10 +++++++---
>>Â 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)
>>ÂÂÂÂÂÂÂ struct dra7xx_pcie *dra7xx = arg;
>>ÂÂÂÂÂÂÂ struct dw_pcie *pci = dra7xx->pci;
>>ÂÂÂÂÂÂÂ struct pcie_port *pp = &pci->pp;
>> -ÂÂÂÂ u32 reg;
>> +ÂÂÂÂ unsigned long reg;
>> +ÂÂÂÂ u32 virq, bit;
>>Â 
>>ÂÂÂÂÂÂÂ reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI);
>>Â 
>> @@ -269,8 +270,11 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
>>ÂÂÂÂÂÂÂ case INTB:
>>ÂÂÂÂÂÂÂ case INTC:
>>ÂÂÂÂÂÂÂ case INTD:
>> -ÂÂÂÂÂÂÂÂÂÂÂÂ generic_handle_irq(irq_find_mapping(dra7xx->irq_domain,
>> -ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ ffs(reg) - 1));
>> +ÂÂÂÂÂÂÂÂÂÂÂÂ for_each_set_bit(bit, &reg, PCI_NUM_INTX) {
>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ virq = irq_find_mapping(dra7xx->irq_domain, bit);
>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ if (virq)
>> +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ generic_handle_irq(virq);
>> +ÂÂÂÂÂÂÂÂÂÂÂÂ }
>>ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ break;
>>ÂÂÂÂÂÂÂ }
> 
> 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