On Mon, Mar 18, 2019 at 08:12:04PM -0500, Alexandru Gagniuc wrote: > A threaded IRQ with a NULL handler does not work with level-triggered > interrupts. request_threaded_irq() will return an error: > > genirq: Threaded irq requested with handler=NULL and !ONESHOT for irq 16 > pcie_bw_notification: probe of 0000:00:1b.0:pcie010 failed with error -22 > > For level interrupts we need to silence the interrupt before exiting > the IRQ handler, so just clear the PCI_EXP_LNKSTA_LBMS bit there. > > Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Alexandru Gagniuc <mr.nuke.me@xxxxxxxxx> I've tested this on my Ivy Bridge MacBook Pro which uses INTx on root and downstream ports and I'm not seeing probe errors, so: Tested-by: Lukas Wunner <lukas@xxxxxxxxx> > @@ -67,8 +77,8 @@ static irqreturn_t pcie_bw_notification_handler(int irq, void *context) > __pcie_print_link_status(dev, false); > up_read(&pci_bus_sem); > > + pcie_capability_read_word(port, PCI_EXP_LNKSTA, &link_status); > pcie_update_link_speed(port->subordinate, link_status); > - pcie_capability_write_word(port, PCI_EXP_LNKSTA, events); > return IRQ_HANDLED; > } I'd suggest leaving the call to pcie_update_link_speed() in pcie_bw_notification_irq() to avoid the duplicate read of the Link Status register. With that addressed, Reviewed-by: Lukas Wunner <lukas@xxxxxxxxx> Thanks, Lukas
