Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753690Ab1EYRH5 (ORCPT ); Wed, 25 May 2011 13:07:57 -0400 Received: from wolverine01.qualcomm.com ([199.106.114.254]:7427 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753167Ab1EYRHz (ORCPT ); Wed, 25 May 2011 13:07:55 -0400 X-IronPort-AV: E=McAfee;i="5400,1158,6357"; a="93609383" Message-ID: In-Reply-To: References: Date: Wed, 25 May 2011 10:07:25 -0700 (PDT) Subject: RE: [PATCH v12 7/8] usb: Adding SuperSpeed support to dummy_hcd From: "Brokhman Tatyana" To: "Alan Stern" Cc: "Tanya Brokhman" , balbi@ti.com, "'Sarah Sharp'" , greg@kroah.com, linux-usb@vger.kernel.org, linux-arm-msm@vger.kernel.org, ablay@codeaurora.org, "'open list'" Reply-To: tlinder@codeaurora.org User-Agent: SquirrelMail/1.4.17 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Priority: 3 (Normal) Importance: Normal Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2422 Lines: 57 Hi Alan, > I have looked this over more carefully. It turns out that both of you > have misunderstood the purpose of CONFIG_USB_GADGET_DUALSPEED (and by > extension, CONFIG_USB_GADGET_SUPERSPEED). In fact, the existing > Kconfig file is also wrong. > > The _only_ reason for CONFIG_USB_GADGET_DUALSPEED is so that gadget > drivers can use conditional compilation to avoid including the > high-speed descriptors when the UDC doesn't support high-speed > operation. That's all. This means that the > CONFIG_USB_GAGDET_DUALSPEED option does not need to be > user-controllable in Kconfig. It should default to N, and UDC drivers > that support high speed should select it. > > The same should be true of CONFIG_USB_GADGET_HIGHSPEED. It should not > be user-controllable. It should default to N, and UDC drivers that > support SuperSpeed operation (after these patches, only dummy-hcd) > should select it. Ok, agreed. Thanks for the clarification. I saw your patch, I'll update mine in the same way. > There remains the other question, about whether composite_driver.speed > should be set to USB_SPEED_SUPER. I think the matter can be settled at > runtime. Iterate through all the function drivers; if all of them > support SuperSpeed and CONFIG_USB_GADGET_SUPERSPEED is enabled then set > composite_driver.speed to USB_SPEED_SUPER. Not sure how to verify this. I need to know whether the driver that is registered with the UDC is SS or not. This is before the function drivers are binded to it. So how can I verify at that point that the function drivers that will bind to this driver will provide SS descriptors? (I'm sorry, I don't have the ability to view the code at the moment and due to the time differences between us I don't want to leave this question for tomorrow and loose another day...) >Otherwise, if all of them > support high speed and CONFIG_USB_GADGET_DUALSPEED is enabled then set > composite_driver.speed to USB_SPEED_HIGH. Otherwise set it to > USB_SPEED_FULL. > > Alan Stern > Thanks, Tanya Brokhman -- Sent by an consultant of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum. -- 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/