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 <o...@mkt-sys.de>
Acked-by: Alan Stern <st...@rowland.harvard.edu>
CC: <sta...@vger.kernel.org>
---
v2: Corrected description, marked for the -stable kernels.
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 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]);
}
}
--
1.9.1
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