Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756979AbaGAOMQ (ORCPT ); Tue, 1 Jul 2014 10:12:16 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:36886 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754308AbaGAOMP (ORCPT ); Tue, 1 Jul 2014 10:12:15 -0400 Date: Tue, 1 Jul 2014 10:12:14 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: "Chen, Alvin" cc: Sergei Shtylyov , , , Boon Leong Ong Subject: Re: [PATCH v4] USB: ehci-pci: USB host controller support for Intel Quark X1000 In-Reply-To: <1404227734-14825-2-git-send-email-alvin.chen@intel.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 1 Jul 2014, Chen, Alvin wrote: > From: Bryan O'Donoghue > > The EHCI packet buffer in/out threshold is programmable for Intel Quark X1000 > USB host controller, and the default value is 0x20 dwords. The in/out threshold > can be programmed to 0x80 dwords (512 Bytes) to maximize the perfomrance, > but only when isochronous/interrupt transactions are not initiated by the USB > host controller. This patch is to reconfigure the packet buffer in/out > threshold as maximal as possible to maximize the performance, and 0x7F dwords > (508 Bytes) should be used because the USB host controller initiates > isochronous/interrupt transactions. > > Signed-off-by: Bryan O'Donoghue > Signed-off-by: Alvin (Weike) Chen Acked-by: Alan Stern There's one error in the style... > diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c > index 3e86bf4..429434d 100644 > --- a/drivers/usb/host/ehci-pci.c > +++ b/drivers/usb/host/ehci-pci.c > @@ -35,6 +35,21 @@ static const char hcd_name[] = "ehci-pci"; > #define PCI_DEVICE_ID_INTEL_CE4100_USB 0x2e70 > > /*-------------------------------------------------------------------------*/ > +#define PCI_DEVICE_ID_INTEL_QUARK_X1000_SOC 0x0939 > +static inline bool is_intel_quark_x1000(struct pci_dev *pdev) > +{ > + return pdev->vendor == PCI_VENDOR_ID_INTEL && > + pdev->device == PCI_DEVICE_ID_INTEL_QUARK_X1000_SOC; > +} > + > +/* > + * 0x84 is the offset of in/out threshold register, > + * and it is the same offset as the register of 'hostpc'. > + */ This comment isn't formatted right. It should be like this: /* * blah blah blah * blah blah blah */ If you want to submit a corrected version, you can. Or Greg may be willing to fix the style when he merges this patch. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/