Dear Bjørn Erik Nilsen,
[...]
> > > Thank you for your effort!
> > > I reproduced this kernel panic on Exynos platform with LAN card.
> > > And then, I tested your patch and checked this kernel panic is
> > > resolved.
> > >
> > > Marek Vasut,
> > > Will you test Bjørn Erik Nilsen's patch with your i.MX platform?
> > >
> > > Pratyush Anand,
> > > Would you confirm Bjørn Erik Nilsen's patch?
> > >
> > > I will do more extensive testing.
> > > Thank you.
> >
> > The patch does indeed fix the crash, but there are more subtle issues
> > lurking around. I noticed how irq numbers were constantly increasing and
> > I found at least one stupid mistake that I made.
> >
> > > - irq_set_msi_desc(irq + i, desc);
> > > + irq_set_msi_desc_off(irq + i, i, desc);
> >
> > That should be 'irq_set_msi_desc_off(irq, i, desc)'
> >
> > (I'm really puzzled why this didn't cause other oops ...)
> >
> > I also realized that teardown() is only called for the irq returned from
> > setup(), which kind of makes sense since the others are destroyed() in
> > the first call to teardown. This means we need to iterate all irqs in
> > the same fashion as we allocate in setup/assign_irq. Basically unrolling
> > what was done there.
> >
> > I'm hacking on this solution now but it doesn't quite take me to where I
> > want at the moment, so it would be nice if someone with a better
> > understanding of the code could pitch in.
>
> I gave it another shot and now it starts to look like something. At
> least I get consistent irq numbers and my system is very stable in
> general.
>
> My new patch does exactly the opposite in teardown() of what is done in
> setup(), which in itself is a good sign.
>
> --- pcie-designware.c.orig 2013-11-21 14:02:03.656007695 +0100
> +++ pcie-designware.c 2013-11-22 16:32:30.360954591 +0100
> @@ -242,11 +242,15 @@ static int assign_irq(int no_irqs, struc
> if (!irq)
> goto no_valid_irq;
>
> + /*
> + * irq_domain_add_linear (called from dw_pcie_host_init)
> pre-allocates + * descs so there is no need to call irq_alloc_descs
> here. + */
> +
> i = 0;
> while (i < no_irqs) {
> set_bit(pos0 + i, pp->msi_irq_in_use);
> - irq_alloc_descs((irq + i), (irq + i), 1, 0);
> - irq_set_msi_desc(irq + i, desc);
> + irq_set_msi_desc_off(irq, i, desc);
Why do you not allocate the descs anymore ?
> /*Enable corresponding interrupt in MSI interrupt
> controller */ res = ((pos0 + i) / 32) * 12;
> bit = (pos0 + i) % 32;
> @@ -266,7 +270,7 @@ no_valid_irq:
>
> static void clear_irq(unsigned int irq)
> {
> - int res, bit, val, pos;
> struct irq_desc *desc;
> struct msi_desc *msi;
> struct pcie_port *pp;
> @@ -281,18 +285,28 @@ static void clear_irq(unsigned int irq)
> return;
> }
>
> + /* undo what was done in assign_irq */
> pos = data->hwirq;
> + nvec = 1 << msi->msi_attrib.multiple;
>
> - irq_free_desc(irq);
> -
> - clear_bit(pos, pp->msi_irq_in_use);
> + i = 0;
> + while (i < nvec) {
> + clear_bit(pos + i, pp->msi_irq_in_use);
> + irq_set_msi_desc_off(irq, i, NULL);
> + /* Disable corresponding interrupt on MSI interrupt
> controller */ + res = ((pos + i) / 32) * 12;
> + bit = (pos + i) % 32;
> + dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4,
> &val); + val &= ~(1 << bit);
> + dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4,
> val); + ++i;
> + }
>
> - /* Disable corresponding interrupt on MSI interrupt controller */
> - res = (pos / 32) * 12;
> - bit = pos % 32;
> - dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
> - val &= ~(1 << bit);
> - dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val);
> + msi->msg.address_lo = 0;
> + msi->msg.address_hi = 0;
> + msi->msg.data = 0;
> + msi->irq = 0;
> + msi->msi_attrib.multiple = 0;
> }
>
> static int dw_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev,
> @@ -320,15 +334,14 @@ static int dw_msi_setup_irq(struct msi_c
> if (irq < 0)
> return irq;
>
> - msg_ctr &= ~PCI_MSI_FLAGS_QSIZE;
> - msg_ctr |= msgvec << 4;
> - pci_write_config_word(pdev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
> - msg_ctr);
> desc->msi_attrib.multiple = msgvec;
> -
> msg.address_lo = virt_to_phys((void *)pp->msi_data);
> msg.address_hi = 0x0;
> msg.data = pos;
> + /*
> + * write_msi_msg() will update PCI_MSI_FLAGS so there
> + * is no need to explicitly call pci_write_config here
> + */
> write_msi_msg(irq, &msg);
>
> return 0;
>
>
> Best regards,
>
> Bjørn Erik Nilsen
Can you try using 'git send-email' for submitting subsequent patches please?
The patch works back and forth, I can 'remove' the card with:
echo 1 > /sys/bus/pci/devices/0000:01:00.0/remove
and then 'rescan' the card with:
echo 1 > /sys/bus/pci/devices/0000:00:00.0/rescan
Tested-by: Marek Vasut <marex@xxxxxxx>
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