pciehp: Add missing memory barrier
Fix the possible race condition between pcie_isr() and pciehp_write_cmd()
because of the lack of memory barrier.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 51a5055..19eba2a 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -279,6 +279,7 @@
slot_ctrl |= ((cmd & mask) | CMD_CMPL_INTR_ENABLE);
ctrl->cmd_busy = 1;
+ smp_mb();
retval = pciehp_writew(ctrl, SLOTCTRL, slot_ctrl);
if (retval)
err("%s: Cannot write to SLOTCTRL register\n", __func__);
@@ -759,6 +760,7 @@
/* Check Command Complete Interrupt Pending */
if (intr_loc & CMD_COMPLETED) {
ctrl->cmd_busy = 0;
+ smp_mb();
wake_up_interruptible(&ctrl->queue);
}