On Sun, 01 Nov 2020 09:25:04 +0000,
Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx> wrote:
>
> Am 31. Oktober 2020 22:49:14 MEZ schrieb Thomas Gleixner <tglx@xxxxxxxxxxxxx>:
>
> >That's not a fix. It's just supressing the warning.
>
> Ok sorry
>
> >So it needs to be figured out why the domain association is not there.
>
> It looks like for mt7623 there is no msi domain setup (done via
> mtk_pcie_setup_irq callback + mtk_pcie_init_irq_domain) in mtk pcie
> driver.
Does this mean that this SoC never handled MSIs the first place? Which
would explain the warning, as there is no MSI domain registered for
the device, and we end-up falling back to arch_setup_msi_irqs().
If this system truly is unable to handle MSIs, one potential
workaround would be to register a PCI-MSI domain that would always
fail its allocation with -ENOSPC. It is really ugly, but would keep
the horror localised. See the patchlet below, which I can't test.
If this situation is more common than we expect, we may need something
in core code instead.
M.
diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
index cf4c18f0c25a..52758b546d40 100644
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -151,6 +151,7 @@ struct mtk_pcie_port;
struct mtk_pcie_soc {
bool need_fix_class_id;
bool need_fix_device_id;
+ bool no_msi;
unsigned int device_id;
struct pci_ops *ops;
int (*startup)(struct mtk_pcie_port *port);
@@ -435,6 +436,9 @@ static int mtk_pcie_irq_domain_alloc(struct irq_domain *domain, unsigned int vir
struct mtk_pcie_port *port = domain->host_data;
unsigned long bit;
+ if (port->pcie->soc->no_msi)
+ return -ENOSPC;
+
WARN_ON(nr_irqs != 1);
mutex_lock(&port->lock);
@@ -966,11 +970,13 @@ static int mtk_pcie_parse_port(struct mtk_pcie *pcie,
port->slot = slot;
port->pcie = pcie;
- if (pcie->soc->setup_irq) {
+ if (pcie->soc->setup_irq)
err = pcie->soc->setup_irq(port, node);
- if (err)
- return err;
- }
+ else
+ err = mtk_pcie_allocate_msi_domains(port);
+
+ if (err)
+ return err;
INIT_LIST_HEAD(&port->list);
list_add_tail(&port->list, &pcie->ports);
@@ -1173,6 +1179,7 @@ static const struct dev_pm_ops mtk_pcie_pm_ops = {
};
static const struct mtk_pcie_soc mtk_pcie_soc_v1 = {
+ .no_msi = true,
.ops = &mtk_pcie_ops,
.startup = mtk_pcie_startup_port,
};
--
Without deviation from the norm, progress is not possible.
