[+cc Borislav]
Hi Borislav, sorry; I meant to cc: you when I applied the patch below.
I did add a Reported-by for you.
On Mon, Mar 25, 2019 at 05:25:02PM -0500, Bjorn Helgaas wrote:
> On Fri, Mar 22, 2019 at 07:36:51PM -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.
> >
> > Fixes: e8303bb7a75c ("PCI/LINK: Report degraded links via link bandwidth
> > notification")
> > Reported-by: Linus Torvalds <torva...@linux-foundation.org>
> > Signed-off-by: Alexandru Gagniuc <mr.nuke...@gmail.com>
>
> Applied with the following subject line to for-linus for v5.1, thanks!
>
> PCI/LINK: Supply IRQ handler so level-triggered IRQs are acked
>
> > ---
> > Changes since v1:
> > - move pcie_update_link_speed() to irq to prevent duplicate read of
> > link_status
> > - Add Fixes: to commit message
> >
> > drivers/pci/pcie/bw_notification.c | 19 ++++++++++++++-----
> > 1 file changed, 14 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/pci/pcie/bw_notification.c
> > b/drivers/pci/pcie/bw_notification.c
> > index d2eae3b7cc0f..c48746f1cf3c 100644
> > --- a/drivers/pci/pcie/bw_notification.c
> > +++ b/drivers/pci/pcie/bw_notification.c
> > @@ -44,11 +44,10 @@ static void
> > pcie_disable_link_bandwidth_notification(struct pci_dev *dev)
> > pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctl);
> > }
> >
> > -static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
> > +static irqreturn_t pcie_bw_notification_irq(int irq, void *context)
> > {
> > struct pcie_device *srv = context;
> > struct pci_dev *port = srv->port;
> > - struct pci_dev *dev;
> > u16 link_status, events;
> > int ret;
> >
> > @@ -58,6 +57,17 @@ static irqreturn_t pcie_bw_notification_handler(int irq,
> > void *context)
> > if (ret != PCIBIOS_SUCCESSFUL || !events)
> > return IRQ_NONE;
> >
> > + pcie_capability_write_word(port, PCI_EXP_LNKSTA, events);
> > + pcie_update_link_speed(port->subordinate, link_status);
> > + return IRQ_WAKE_THREAD;
> > +}
> > +
> > +static irqreturn_t pcie_bw_notification_handler(int irq, void *context)
> > +{
> > + struct pcie_device *srv = context;
> > + struct pci_dev *port = srv->port;
> > + struct pci_dev *dev;
> > +
> > /*
> > * Print status from downstream devices, not this root port or
> > * downstream switch port.
> > @@ -67,8 +77,6 @@ static irqreturn_t pcie_bw_notification_handler(int irq,
> > void *context)
> > __pcie_print_link_status(dev, false);
> > up_read(&pci_bus_sem);
> >
> > - pcie_update_link_speed(port->subordinate, link_status);
> > - pcie_capability_write_word(port, PCI_EXP_LNKSTA, events);
> > return IRQ_HANDLED;
> > }
> >
> > @@ -80,7 +88,8 @@ static int pcie_bandwidth_notification_probe(struct
> > pcie_device *srv)
> > if (!pcie_link_bandwidth_notification_supported(srv->port))
> > return -ENODEV;
> >
> > - ret = request_threaded_irq(srv->irq, NULL, pcie_bw_notification_handler,
> > + ret = request_threaded_irq(srv->irq, pcie_bw_notification_irq,
> > + pcie_bw_notification_handler,
> > IRQF_SHARED, "PCIe BW notif", srv);
> > if (ret)
> > return ret;
> > --
> > 2.19.2
> >
