[PATCH] USB: EHCI port tweaks
One change may improve some S1 or S3 resume cases, and the other
seems mostly to explain some strange state "lsusb" would show.
Two fixes:
- On resume, don't think about resuming any unpowered port, or
resetting any port with OWNER set to the OHCI/UHCI companion.
This will make some S1 and S3 resume scenarios work better.
- PORT_CSC was not being cleared correctly in ehci_hub_status_data.
This was visible at least through current versions of "lsusb",
and might have caused some other hub related strangeness.
The fix addresses all three write-to-clear bits, using the same
approach that UHCI happens to use: a mask of bits that are
cleared in most writes to that port status register.
Original patch seems to have been from from William.Morrow@amd.com
and this version (from David) finishes the write-to-clear changes.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 2507e89..2f7037c 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -759,12 +759,16 @@
if (time_before (jiffies, ehci->next_statechange))
msleep (100);
- /* If any port is suspended, we know we can/must resume the HC. */
+ /* If any port is suspended (or owned by the companion),
+ * we know we can/must resume the HC (and mustn't reset it).
+ */
for (port = HCS_N_PORTS (ehci->hcs_params); port > 0; ) {
u32 status;
port--;
status = readl (&ehci->regs->port_status [port]);
- if (status & PORT_SUSPEND) {
+ if (!(status & PORT_POWER))
+ continue;
+ if (status & (PORT_SUSPEND | PORT_OWNER)) {
down (&hcd->self.root_hub->serialize);
retval = ehci_hub_resume (hcd);
up (&hcd->self.root_hub->serialize);