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authorMing Lei <ming.lei@canonical.com>2012-05-19 23:11:19 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-05-19 09:31:29 -0700
commit1c01f1d9a603ecf1744ae2d1a015c4b27c2b9fa0 (patch)
treec8a945d9c09d055c24ebe3780853ed5a8852a11e /drivers/usb
parent4e09dcf20f7b5358615514c2ec8584b248ab8874 (diff)
downloadop-kernel-dev-1c01f1d9a603ecf1744ae2d1a015c4b27c2b9fa0.zip
op-kernel-dev-1c01f1d9a603ecf1744ae2d1a015c4b27c2b9fa0.tar.gz
USB: EHCI: fix command register configuration lost problem
The 3d9545cc375d117554a9b35dfddadf9189c62775(EHCI: maintain the ehci->command value properly) introducs one command register configuration lost problem by the below line in ehci_reset: ehci->command = ehci_readl(ehci, &ehci->regs->command); After writting RESET into command register, it is restored to its default value per EHCI spec[1], so the previous configuration will be lost, and may introduce some problems reported recently: - imx51 Babbage board detect usb hub failed[2], reported by Richard Zhao. - mouse and keyboard hangs in linux-next found by Dan Carpenter and Greg-KH. So this patch just removes the line to fix these problems, and keep configurating command register consistent as before the commit 3d9545cc(EHCI: maintain the ehci->command value properly). [1], 4.1 Host Controller Initialization of EHCI Specification 1.0 [2], failed dmesg log: usb 1-1: new high-speed USB device number 2 using mxc-ehci hub 1-1:1.0: USB hub found hub 1-1:1.0: 7 ports detected mxc-ehci mxc-ehci.1: fatal error mxc-ehci mxc-ehci.1: HC died; cleaning up mxc-ehci mxc-ehci.1: force halt; handshake f5780344 00004000 00004000 -> -110 mxc-ehci mxc-ehci.1: HC died; cleaning up usb 1-1: USB disconnect, device number 2 Reported-by: Richard Zhao <richard.zhao@freescale.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Chen Peter-B29397 <B29397@freescale.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/host/ehci-hcd.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index f644ba9..5597e60 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -352,7 +352,6 @@ static int ehci_reset (struct ehci_hcd *ehci)
if (ehci->debug)
dbgp_external_startup();
- ehci->command = ehci_readl(ehci, &ehci->regs->command);
ehci->port_c_suspend = ehci->suspended_ports =
ehci->resuming_ports = 0;
return retval;
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