The STS_HALT is not set until the CRR (CMD_RING_RUNNING) is cleared
on specific xHCI controllers (e.g. R-Car SoCs) after this driver set
the R/S (CMD_RUN) to 0. So, to avoid using a quirks XHCI_SLOW_SUSPEND,
this patch adds to wait for the CRR to clear.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
My environment (R-Car H2) could work correctly. I would like to know
that this patch causes side effect or not. Also I'd like to know
this patch can avoid the XHCI_SLOW_SUSPEND quirk on other environment
(Fresco Logic XHCI controller).
Changes from v1:
- Remove a abort code.
- Wait for the CRR to clear after this driver set the R/S to 0.
- Rebase on the usb.git / usb-next branch.
(commit id = aa519be34f45954f33a6c20430deac8e544a180f)
drivers/usb/host/xhci.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index ec8ac16..a357917 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -923,6 +923,15 @@ int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup)
command &= ~CMD_RUN;
writel(command, &xhci->op_regs->command);
+ /*
+ * The STS_HALT is not set until the CRR is cleared on specific
+ * xHCI controllers (e.g. R-Car SoCs) after this driver set the R/S
+ * to 0. So, to avoid using a quirks XHCI_SLOW_SUSPEND, this driver
+ * waits for the CRR to clear.
+ */
+ xhci_handshake(&xhci->op_regs->cmd_ring, CMD_RING_RUNNING, 0,
+ 5 * 1000 * 1000);
+
/* Some chips from Fresco Logic need an extraordinary delay */
delay *= (xhci->quirks & XHCI_SLOW_SUSPEND) ? 10 : 1;
--
1.9.1
--
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