From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20111102221450.253854558@clark.kroah.org> Date: Wed, 02 Nov 2011 15:13:28 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Wang Zhi , Alan Stern Subject: [002/107] USB: EHCI: Do not rely on PORT_SUSPEND to stop USB resuming in ehci_bus_resume(). In-Reply-To: <20111102221600.GA26650@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Wang Zhi commit d0f2fb2500b1c5fe4967eb45d8c9bc758d7aef80 upstream. >>>From EHCI Spec p.28 HC should clear PORT_SUSPEND when SW clears PORT_RESUME. In Intel Oaktrail platform, MPH (Multi-Port Host Controller) core clears PORT_SUSPEND directly when SW sets PORT_RESUME bit. If we rely on PORT_SUSPEND bit to stop USB resume, we will miss the action of clearing PORT_RESUME. This will cause unexpected long resume signal on USB bus. Signed-off-by: Wang Zhi Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hub.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -243,7 +243,7 @@ static int ehci_bus_resume (struct usb_h u32 temp; u32 power_okay; int i; - u8 resume_needed = 0; + unsigned long resume_needed = 0; if (time_before (jiffies, ehci->next_statechange)) msleep(5); @@ -307,7 +307,7 @@ static int ehci_bus_resume (struct usb_h if (test_bit(i, &ehci->bus_suspended) && (temp & PORT_SUSPEND)) { temp |= PORT_RESUME; - resume_needed = 1; + set_bit(i, &resume_needed); } ehci_writel(ehci, temp, &ehci->regs->port_status [i]); } @@ -322,8 +322,7 @@ static int ehci_bus_resume (struct usb_h i = HCS_N_PORTS (ehci->hcs_params); while (i--) { temp = ehci_readl(ehci, &ehci->regs->port_status [i]); - if (test_bit(i, &ehci->bus_suspended) && - (temp & PORT_SUSPEND)) { + if (test_bit(i, &resume_needed)) { temp &= ~(PORT_RWC_BITS | PORT_RESUME); ehci_writel(ehci, temp, &ehci->regs->port_status [i]); ehci_vdbg (ehci, "resumed port %d\n", i + 1);