diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_uncore.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_uncore.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index 9ac501bcfdad..661b50191f2b 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -465,6 +465,22 @@ fpga_check_for_unclaimed_mmio(struct intel_uncore *uncore) if (likely(!(dbg & FPGA_DBG_RM_NOCLAIM))) return false; + /* + * Bugs in PCI programming (or failing hardware) can occasionally cause + * us to lose access to the MMIO BAR. When this happens, register + * reads will come back with 0xFFFFFFFF for every register and things + * go bad very quickly. Let's try to detect that special case and at + * least try to print a more informative message about what has + * happened. + * + * During normal operation the FPGA_DBG register has several unused + * bits that will always read back as 0's so we can use them as canaries + * to recognize when MMIO accesses are just busted. + */ + if (unlikely(dbg == ~0)) + drm_err(&uncore->i915->drm, + "Lost access to MMIO BAR; all registers now read back as 0xFFFFFFFF!\n"); + __raw_uncore_write32(uncore, FPGA_DBG, FPGA_DBG_RM_NOCLAIM); return true; @@ -1780,7 +1796,7 @@ static int i915_pmic_bus_access_notifier(struct notifier_block *nb, static int uncore_mmio_setup(struct intel_uncore *uncore) { struct drm_i915_private *i915 = uncore->i915; - struct pci_dev *pdev = i915->drm.pdev; + struct pci_dev *pdev = to_pci_dev(i915->drm.dev); int mmio_bar; int mmio_size; @@ -1812,7 +1828,7 @@ static int uncore_mmio_setup(struct intel_uncore *uncore) static void uncore_mmio_cleanup(struct intel_uncore *uncore) { - struct pci_dev *pdev = uncore->i915->drm.pdev; + struct pci_dev *pdev = to_pci_dev(uncore->i915->drm.dev); pci_iounmap(pdev, uncore->regs); } |