[PATCH v3 3/7] PCI: Do not disable memory decoding in pci_reassigndev_resource_alignment()
From: Yongji Xie <hidden>
Date: 2016-06-30 10:54:42
Also in:
linux-pci, lkml
Subsystem:
pci subsystem, the rest · Maintainers:
Bjorn Helgaas, Linus Torvalds
We should not disable memory decoding when we reassign alignment in pci_reassigndev_resource_alignment(). It's meaningless and have some side effect. For example, some fixup functions such as quirk_e100_interrupt() read PCI_COMMAND_MEMORY to know whether the devices has been initialized by the firmware or not. If we disable memory decoding here, these functions will get a wrong information that the devices was not initialized by the firmware which may cause a wrong fixup. Besides, disabling memory decoding may also break some devices that need to have memory decoding always-on during probing. Signed-off-by: Yongji Xie <redacted> --- drivers/pci/pci.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6ae02de..6241cfc 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c@@ -4820,7 +4820,6 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) int i; struct resource *r; resource_size_t align, size; - u16 command; /* We should never try to reassign VF's alignment */ if (dev->is_virtfn)
@@ -4838,12 +4837,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) return; } - dev_info(&dev->dev, - "Disabling memory decoding and releasing memory resources.\n"); - pci_read_config_word(dev, PCI_COMMAND, &command); - command &= ~PCI_COMMAND_MEMORY; - pci_write_config_word(dev, PCI_COMMAND, command); - + dev_info(&dev->dev, "Releasing memory resources.\n"); for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) { r = &dev->resource[i]; if (!(r->flags & IORESOURCE_MEM))
--
1.7.9.5