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usb: ehci: change order of register cleanup during shutdown

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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>
This commit is contained in:
Marc Ohlf 2016-08-03 11:51:54 +02:00 committed by Greg Kroah-Hartman
parent aed9d65ac3
commit bc337b5150
1 changed files with 2 additions and 2 deletions
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4
drivers/usb/host/ehci-hcd.c
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@ -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]);
}
}