x86/pci/intel_mid_pci: Work around for IRQ0 assignment (39d9b77b) · Commits · e / devices / android_kernel_teracube_2e

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: (serial: 8250_pci: add Intel Tangier support) Signed-off-by:

Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Link: http://lkml.kernel.org/r/1438161409-4671-2-git-send-email-andriy.shevchenko@linux.intel.com Signed-off-by:

Thomas Gleixner <tglx@linutronix.de>

arch/x86/pci/intel_mid_pci.c

+22 −2

Original line number	Diff line number	Diff line
		@@ -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);

		/*