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Commit 04b55c47 authored by Shmulik Ravid's avatar Shmulik Ravid Committed by Jesse Barnes
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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: default avatarShmulik Ravid <shmulikr@broadcom.com>
Signed-off-by: default avatarJesse 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;