Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 3 Nov 2010 17:04:44 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [RFC/RFT] OHCI: Fix for regression in 2.6.37-rc1 since commit 3df7169e7 |
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On Wed, 3 Nov 2010, Larry Finger wrote:
> Following commit 3df7169e73fc1d71a39cffeacc969f6840cdf52b, my logs are spammed > with messages of the form "hub 2-0:1.0: unable to enumerate USB device on > port 5". > > Experimentation has shown that if the functional state bits of the control > register are preserved in the fixup, then the messages no longer appear. > > Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> > --- > > Pali, > > Is it possible for you to test this patch to ensure that it does not interfere > with the fix for the shutdown problem. > > Thanks, > > Larry > --- > > Index: linux-realtek/drivers/usb/host/pci-quirks.c > =================================================================== > --- linux-realtek.orig/drivers/usb/host/pci-quirks.c > +++ linux-realtek/drivers/usb/host/pci-quirks.c > @@ -35,6 +35,7 @@ > #define OHCI_INTRENABLE 0x10 > #define OHCI_INTRDISABLE 0x14 > #define OHCI_OCR (1 << 3) /* ownership change request */ > +#define OHCI_CTRL_HCFS (3 << 6) /* functional state */ > #define OHCI_CTRL_RWC (1 << 9) /* remote wakeup connected */ > #define OHCI_CTRL_IR (1 << 8) /* interrupt routing */ > #define OHCI_INTR_OC (1 << 30) /* ownership change */ > @@ -184,7 +185,7 @@ static void __devinit quirk_usb_handoff_ > #ifdef __hppa__ > #define OHCI_CTRL_MASK (OHCI_CTRL_RWC | OHCI_CTRL_IR) > #else > -#define OHCI_CTRL_MASK OHCI_CTRL_RWC > +#define OHCI_CTRL_MASK (OHCI_CTRL_RWC | OHCI_CTRL_HCFS) > > if (control & OHCI_CTRL_IR) { > int wait_time = 500; /* arbitrary; 5 seconds */
This patch is definitely wrong -- it defeats the entire purpose of rewriting the control register! That write was added _specifically_ to put the controller into reset, i.e., to change the functional state.
Furthermore, the write does the same thing as ohci_hcd.c does in its ohci_usb_reset() routine. Regardless, ohci_run() does a complete host controller reset, which should override anything done in pci-quirks.c. Perhaps _that_ routine needs some attention.
Alan Stern
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