On Intel Tangier the MMC host controller is wired up to irq 0. But several
other devices have irq 0 associated as well due to a bogus PCI configuration.
The first initialized driver will acquire irq 0 and make it unavailable for
other devices. If the sdhci driver is not the first one it will fail to acquire
the interrupt and therefor be non functional.
Add a quirk to the pci irq enable function which denies irq 0 to anything else
than the MMC host controller driver on Tangier platforms.
Fixes: 90b9aacf912a (serial: 8250_pci: add Intel Tangier support)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
arch/x86/pci/intel_mid_pci.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)
diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c
index 2706230..7553921 100644
--- a/arch/x86/pci/intel_mid_pci.c
+++ b/arch/x86/pci/intel_mid_pci.c
@@ -35,6 +35,9 @@
#define PCIE_CAP_OFFSET 0x100
+/* Quirks for the listed devices */
+#define PCI_DEVICE_ID_INTEL_MRFL_MMC 0x1190
+
/* Fixed BAR fields */
#define PCIE_VNDR_CAP_ID_FIXED_BAR 0x00 /* Fixed BAR (TBD) */
#define PCI_FIXED_BAR_0_SIZE 0x04
@@ -214,10 +217,27 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev)
if (dev->irq_managed && dev->irq > 0)
return 0;
- if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
+ switch (intel_mid_identify_cpu()) {
+ case INTEL_MID_CPU_CHIP_TANGIER:
polarity = 0; /* active high */
- else
+
+ /* Special treatment for IRQ0 */
+ if (dev->irq == 0) {
+ /*
+ * TNG has IRQ0 assigned to eMMC controller. But there
+ * are also other devices with bogus PCI configuration
+ * that have IRQ0 assigned. This check ensures that
+ * eMMC gets it.
+ */
+ if (dev->device != PCI_DEVICE_ID_INTEL_MRFL_MMC)
+ return -EBUSY;
+ }
+ break;
+ default:
polarity = 1; /* active low */
+ break;
+ }
+
ioapic_set_alloc_attr(&info, dev_to_node(&dev->dev), 1, polarity);
/*
--
2.4.6
--
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