From bb27570525a71f48347ed0e0c265063e7952bb61 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 13 Jun 2016 21:28:00 +0300 Subject: [PATCH] x86/platform/intel_mid_pci: Rework IRQ0 workaround On Intel Merrifield platform several PCI devices have a bogus configuration, i.e. the IRQ0 had been assigned to few of them. These are PCI root bridge, eMMC0, HS UART common registers, PWM, and HDMI. The actual interrupt line can be allocated to one device exclusively, in our case to eMMC0, the rest should cope without it and basically known drivers for them are not using interrupt line at all. Rework IRQ0 workaround, which was previously done to avoid conflict between eMMC0 and HS UART common registers, to behave differently based on the device in question, i.e. allocate interrupt line to eMMC0, but silently skip interrupt allocation for the rest except HS UART common registers which are not used anyway. With this rework IOSF MBI driver in particular would be used. Signed-off-by: Andy Shevchenko Acked-by: Thomas Gleixner Cc: Bjorn Helgaas Cc: Linus Torvalds Cc: Peter Zijlstra Fixes: 39d9b77b8deb ("x86/pci/intel_mid_pci: Work around for IRQ0 assignment") Link: http://lkml.kernel.org/r/1465842481-136852-1-git-send-email-andriy.shevchenko@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/pci/intel_mid_pci.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c index 8b93e634af84..ae97f24a4371 100644 --- a/arch/x86/pci/intel_mid_pci.c +++ b/arch/x86/pci/intel_mid_pci.c @@ -37,6 +37,7 @@ /* Quirks for the listed devices */ #define PCI_DEVICE_ID_INTEL_MRFL_MMC 0x1190 +#define PCI_DEVICE_ID_INTEL_MRFL_HSU 0x1191 /* Fixed BAR fields */ #define PCIE_VNDR_CAP_ID_FIXED_BAR 0x00 /* Fixed BAR (TBD) */ @@ -224,14 +225,21 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev) /* Special treatment for IRQ0 */ if (dev->irq == 0) { + /* + * Skip HS UART common registers device since it has + * IRQ0 assigned and not used by the kernel. + */ + if (dev->device == PCI_DEVICE_ID_INTEL_MRFL_HSU) + return -EBUSY; /* * 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. + * eMMC gets it. The rest of devices still could be + * enabled without interrupt line being allocated. */ if (dev->device != PCI_DEVICE_ID_INTEL_MRFL_MMC) - return -EBUSY; + return 0; } break; default: -- 2.30.2