From: Marc Ohlf <ohlf@mkt-sys.de>
Date: Wed, 3 Aug 2016 09:51:54 +0000 (+0200)
Subject: usb: ehci: change order of register cleanup during shutdown
X-Git-Tag: v4.8~191^2~11
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bc337b51508beb2d039aff5074a76cfe1c212030;p=platform%2Fkernel%2Flinux-amlogic.git

usb: ehci: change order of register cleanup during shutdown

In ehci_turn_off_all_ports() all EHCI port registers are cleared to zero.
On some hardware, this can lead to an system hang,
when ehci_port_power() accesses the already cleared registers.

This patch changes the order of cleanup.
First call ehci_port_power() which respects the current bits in
port status registers
and afterwards cleanup the hard way by setting everything to zero.

Signed-off-by: Marc Ohlf <ohlf@mkt-sys.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index a962b89..1e5f529 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -332,11 +332,11 @@ static void ehci_turn_off_all_ports(struct ehci_hcd *ehci)
 	int	port = HCS_N_PORTS(ehci->hcs_params);
 
 	while (port--) {
-		ehci_writel(ehci, PORT_RWC_BITS,
-				&ehci->regs->port_status[port]);
 		spin_unlock_irq(&ehci->lock);
 		ehci_port_power(ehci, port, false);
 		spin_lock_irq(&ehci->lock);
+		ehci_writel(ehci, PORT_RWC_BITS,
+				&ehci->regs->port_status[port]);
 	}
 }