Hi Ben,
On: 25/03/2014 17:05, Ben wrote:
> Subject: Re: [PATCH v5 2/9] PCI: host: rcar: Add MSI support
>
> On 25/03/14 16:56, Phil Edworthy wrote:
> > Signed-off-by: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
> > ---
> > v5:
> > - Return IRQ_NONE from MSI isr when there is no pending MSI
> > - Add additional interrupt bindings
> > +
> > +static void rcar_msi_free(struct rcar_msi *chip, unsigned long irq)
> > +{
> > + struct device *dev = chip->chip.dev;
> > +
> > + mutex_lock(&chip->lock);
> > +
> > + if (!test_bit(irq, chip->used))
> > + dev_err(dev, "trying to free unused MSI#%lu\n", irq);
>
> Does the upper level not check for this?
Yes, the default_teardown_msi_irqs function checks for unused MSIs, so we
don't really need to check here.
> > + else
> > + clear_bit(irq, chip->used);
> > +
> > + mutex_unlock(&chip->lock);
>
>
> > +}
> > +
> > +static irqreturn_t rcar_pcie_msi_irq(int irq, void *data)
> > +{
> > + struct rcar_pcie *pcie = data;
> > + struct rcar_msi *msi = &pcie->msi;
> > + unsigned long reg;
> > +
> > + reg = pci_read_reg(pcie, PCIEMSIFR);
> > +
> > + /* MSI & INTx share an interrupt - we only handle MSI here */
> > + if (!reg)
> > + return IRQ_NONE;
> > +
> > + while (reg) {
> > + unsigned int index = find_first_bit(®, 32);
> > + unsigned int irq;
> > +
> > + /* clear the interrupt */
> > + pci_write_reg(pcie, 1 << index, PCIEMSIFR);
> > +
> > + irq = irq_find_mapping(msi->domain, index);
> > + if (irq) {
> > + if (test_bit(index, msi->used))
> > + generic_handle_irq(irq);
> > + else
> > + dev_info(pcie->dev, "unhandled MSI\n");
> > + } else {
> > + /*
> > + * that's weird who triggered this?
> > + * just clear it
> > + */
> > + dev_info(pcie->dev, "unexpected MSI\n");
> > + }
>
> You may want to change this to something that is either rate-limited
> or is say debug level so it does not spam the console if something
> does go wrong.
I'll change that to debug level.
> Also the comment could easily be made one line
> /* Weird, unknown MSI IRQ, just clear it */
Sure!
Thanks
Phil
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