See my comments below: > -----Original Message----- > From: Greg Kroah-Hartman [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] > Sent: Tuesday, June 24, 2014 9:25 PM > To: Chen, Alvin > Cc: Alan Stern; linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Ong, > Boon Leong > Subject: Re: [PATCH] USB: ehci-pci: USB host controller support for Intel Quark > X1000 > > On Tue, Jun 24, 2014 at 08:51:43AM -0700, Chen, Alvin wrote: > > From: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxx> > > > > This patch is to enable USB host controller for Intel Quark X1000. Add > > pci quirks to adjust the packet buffer in/out threshold value, and > > ensure EHCI packet buffer i/o threshold value is reconfigured to half. > > > > Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxx> > > Signed-off-by: Alvin (Weike) Chen <alvin.chen@xxxxxxxxx> > > --- > > drivers/usb/host/ehci-pci.c | 4 ++++ > > drivers/usb/host/pci-quirks.c | 42 > +++++++++++++++++++++++++++++++++++++++++ > > drivers/usb/host/pci-quirks.h | 2 ++ > > 3 files changed, 48 insertions(+) > > > > diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c > > index 3e86bf4..33cfa23 100644 > > --- a/drivers/usb/host/ehci-pci.c > > +++ b/drivers/usb/host/ehci-pci.c > > @@ -50,6 +50,10 @@ static int ehci_pci_reinit(struct ehci_hcd *ehci, struct > pci_dev *pdev) > > if (!retval) > > ehci_dbg(ehci, "MWI active\n"); > > > > + /* Reset the threshold limit */ > > + if(unlikely(usb_is_intel_qrk(pdev))) > > Why unlikely()? Have you measured a speed difference here? And this is a > _very_ slow path, what does that speed difference you measured help with? > Actually, 'unlikely' is not necessary, I will remove it in PATCH v2. > thanks, > > greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
