Commit 04b55c47 authored Dec 03, 2009 by Shmulik Ravid Committed by Jesse Barnes Dec 04, 2009

PCI: read-modify-write the pcie device control register when initiating pcie flr



The pcie_flr routine writes the device control register with the FLR bit
set clearing all other fields for the FLR duration. Among other fields,
the Max_Payload_Size is also cleared which can cause errors if there are
transactions lurking in the HW pipeline. The patch replaces the blank
write with read-modify-write of the control register keeping the other
fields intact.

Signed-off-by: Shmulik Ravid <shmulikr@broadcom.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

parent bb965401

drivers/pci/pci.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -2140,7 +2140,7 @@ static int pcie_flr(struct pci_dev *dev, int probe)
		int i;
		int pos;
		u32 cap;
		u16 status;
		u16 status, control;

		pos = pci_pcie_cap(dev);
		if (!pos)
		@@ -2167,8 +2167,10 @@ static int pcie_flr(struct pci_dev *dev, int probe)
		"proceeding with reset anyway\n");

		clear:
		pci_write_config_word(dev, pos + PCI_EXP_DEVCTL,
		PCI_EXP_DEVCTL_BCR_FLR);
		pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &control);
		control \|= PCI_EXP_DEVCTL_BCR_FLR;
		pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, control);

		msleep(100);

		return 0;

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