From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH 1/5] USB: gadget: Use Zero Interrupt Threshold Control for ci13xxx_msm Date: Thu, 28 Apr 2011 16:18:17 +0400 Message-ID: <4DB95B09.9000207@ru.mvista.com> References: <1303977693-18389-1-git-send-email-pkondeti@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:33864 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756077Ab1D1MUM (ORCPT ); Thu, 28 Apr 2011 08:20:12 -0400 In-Reply-To: <1303977693-18389-1-git-send-email-pkondeti@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Pavankumar Kondeti Cc: greg@kroah.com, linux-usb@vger.kernel.org, linux-arm-msm@vger.kernel.org, Anji jonnala Hello. On 28-04-2011 12:01, Pavankumar Kondeti wrote: > From: Anji jonnala > ITC (Interrupt Threshold Control) field is to set the maximum rate at which > the device controller will issue interrupts. The maximum interrupt interval > is measured in micro frames. Valid values are 0, 1, 2, 4, 8, 16, 32, 64. > The default value is 8 micro frames. Set ITC to zero for MSM to gain > performance. > Signed-off-by: Anji jonnala > Signed-off-by: Pavankumar Kondeti > --- > drivers/usb/gadget/ci13xxx_msm.c | 3 ++- > drivers/usb/gadget/ci13xxx_udc.c | 11 +++++++++++ > drivers/usb/gadget/ci13xxx_udc.h | 3 +++ > 3 files changed, 16 insertions(+), 1 deletions(-) > diff --git a/drivers/usb/gadget/ci13xxx_udc.c b/drivers/usb/gadget/ci13xxx_udc.c > index e09178b..bd1a059 100644 > --- a/drivers/usb/gadget/ci13xxx_udc.c > +++ b/drivers/usb/gadget/ci13xxx_udc.c > @@ -318,6 +318,17 @@ static int hw_device_reset(struct ci13xxx *udc) > hw_cwrite(CAP_USBMODE, USBMODE_CM, USBMODE_CM_DEVICE); > hw_cwrite(CAP_USBMODE, USBMODE_SLOM, USBMODE_SLOM); /* HW>= 2.3 */ > > + /* > + * ITC (Interrupt Threshold Control) field is to set the maximum > + * rate at which the device controller will issue interrupts. > + * The maximum interrupt interval measured in micro frames. > + * Valid values are 0, 1, 2, 4, 8, 16, 32, 64. The default value is > + * 8 micro frames. If CPU can handle interrupts at faster rate, ITC > + * can be set to lesser value to gain performance. > + */ > + if (udc->udc_driver->flags && CI13XXX_ZERO_ITC) I think you meant bitwise AND (&) here. WBR, Sergei