From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Ott Subject: Re: [PATCH] HID: Add Support for Setting and Getting Feature Reports from hidraw Date: Tue, 08 Jun 2010 09:42:55 -0400 Message-ID: <4C0E48DF.7000006@signal11.us> References: <1275969108-14948-1-git-send-email-alan@signal11.us> <20100608083226.2dac88d2.ospite@studenti.unina.it> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from core.signal11.us ([64.251.29.136]:52874 "EHLO core.signal11.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755138Ab0FHNm7 (ORCPT ); Tue, 8 Jun 2010 09:42:59 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by core.signal11.us (Postfix) with SMTP id DF2231042FD for ; Tue, 8 Jun 2010 09:42:58 -0400 (EDT) In-Reply-To: <20100608083226.2dac88d2.ospite@studenti.unina.it> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Antonio Ospite Cc: Jiri Kosina , Alexey Dobriyan , Tejun Heo , Marcel Holtmann , Alan Stern , Greg Kroah-Hartman , Stephane Chatty , Michael Poole , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org On 06/08/2010 02:32 AM, Antonio Ospite wrote: > On Mon, 7 Jun 2010 23:51:48 -0400 > Alan Ott wrote: > > >> Per the HID Specification, Feature reports must be sent and received on >> the Configuration endpoint (EP 0) through the Set_Report/Get_Report >> interfaces. This patch adds two ioctls to hidraw to set and get feature >> reports to and from the device. Modifications were made to hidraw and >> usbhid. >> >> New hidraw ioctls: >> HIDIOCSFEATURE - Perform a Set_Report transfer of a Feature report. >> HIDIOCGFEATURE - Perform a Get_Report transfer of a Feature report. >> >> Signed-off-by: Alan Ott >> --- >> > Thanks Alan, I am going to test this quite soon. > > TBH, when I was thinking about how to extend hidraw I thought we could > have added a new report_type field to struct hidraw_report_descriptor, > in order to re-use the HIDIOCGRDESC ioctl handler itself, adding then a > HIDIOCSRDESC for setting the report. This looked cleaner to my eyes, > Thanks for the feedback, Antonio. The HIDIOCGRDESC ioctl copies the existing descriptor from the hid_device structure. Since it does not initiate a Get_Report transfer, I'm not sure how much re-use there could have been using that method. In my estimation, a Set_Report/Get_Report was more similar to the call to write(). > but I didn't actually implement this, so I don't know if it was > feasible, for instance one problem I didn't investigate further was > about the default value of the aforementioned report_type field in > order to keep the current behavior of HIDIOCGRDESC. > I'm not sure what you mean here, as the report_type field is not part of hidraw_report_descriptor. Thanks for testing my patch. Please let me know if you have problems with it. Alan.