From: Shmulik Ravid Date: Thu, 3 Dec 2009 20:27:51 +0000 (+0200) Subject: PCI: read-modify-write the pcie device control register when initiating pcie flr X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=04b55c4732780381410e52db0e9bfb7661f2b4b3;p=linux-beck.git 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 Signed-off-by: Jesse Barnes --- diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index be91a09c74a5..6af212c509c5 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -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;