From bc337b51508beb2d039aff5074a76cfe1c212030 Mon Sep 17 00:00:00 2001 From: Marc Ohlf Date: Wed, 3 Aug 2016 11:51:54 +0200 Subject: [PATCH] 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 Acked-by: Alan Stern CC: Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index a962b89b65a6..1e5f529d51a2 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]); } } -- 2.39.2