[PATCH 3.16 014/204] usb: pci-quirks.c: Corrected timeout values used in handshake

From: Ben Hutchings
Date: Thu Dec 28 2017 - 13:06:21 EST


3.16.52-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Jim Dickerson <jim.dickerson@xxxxxxx>

commit 114ec3a6f9096d211a4aff4277793ba969a62c73 upstream.

Servers were emitting failed handoff messages but were not
waiting the full 1 second as designated in section 4.22.1 of
the eXtensible Host Controller Interface specifications. The
handshake was using wrong units so calls were made with milliseconds
not microseconds. Comments referenced 5 seconds not 1 second as
in specs.

The wrong units were also corrected in a second handshake call.

Signed-off-by: Jim Dickerson <jim.dickerson@xxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/usb/host/pci-quirks.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -1024,7 +1024,7 @@ EXPORT_SYMBOL_GPL(usb_disable_xhci_ports
*
* Takes care of the handoff between the Pre-OS (i.e. BIOS) and the OS.
* It signals to the BIOS that the OS wants control of the host controller,
- * and then waits 5 seconds for the BIOS to hand over control.
+ * and then waits 1 second for the BIOS to hand over control.
* If we timeout, assume the BIOS is broken and take control anyway.
*/
static void quirk_usb_handoff_xhci(struct pci_dev *pdev)
@@ -1070,9 +1070,9 @@ static void quirk_usb_handoff_xhci(struc
if (val & XHCI_HC_BIOS_OWNED) {
writel(val | XHCI_HC_OS_OWNED, base + ext_cap_offset);

- /* Wait for 5 seconds with 10 microsecond polling interval */
+ /* Wait for 1 second with 10 microsecond polling interval */
timeout = handshake(base + ext_cap_offset, XHCI_HC_BIOS_OWNED,
- 0, 5000, 10);
+ 0, 1000000, 10);

/* Assume a buggy BIOS and take HC ownership anyway */
if (timeout) {
@@ -1100,7 +1100,7 @@ hc_init:
* operational or runtime registers. Wait 5 seconds and no more.
*/
timeout = handshake(op_reg_base + XHCI_STS_OFFSET, XHCI_STS_CNR, 0,
- 5000, 10);
+ 5000000, 10);
/* Assume a buggy HC and start HC initialization anyway */
if (timeout) {
val = readl(op_reg_base + XHCI_STS_OFFSET);