From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sinan Kaya Subject: Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver Date: Wed, 20 Jan 2016 17:18:29 -0500 Message-ID: <56A007B5.9070502@codeaurora.org> References: <1452523550-8920-1-git-send-email-okaya@codeaurora.org> <1452523550-8920-4-git-send-email-okaya@codeaurora.org> <20160115145629.GI3262@leverpostej> <56990CD4.6020405@arm.com> <20160115153656.GM3262@leverpostej> <569917C7.9000804@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <569917C7.9000804@codeaurora.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, arnd@arndb.de, Marc Zyngier , jcm@redhat.com, timur@codeaurora.org, linux-kernel@vger.kernel.org, vinod.koul@intel.com, agross@codeaurora.org, dmaengine@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-msm@vger.kernel.org List-Id: devicetree@vger.kernel.org Mark, On 1/15/2016 11:01 AM, Sinan Kaya wrote: >> I'm concerned with how this is safe, and with the userspace interface. >> > e.g. if the user wants to up the QoS for a VM, how to they find the >> > right channel in sysfs to alter? > The HW supports changing the QoS values on the flight. In order to locate the > object, I'm exporting a > > I tried to address your concern on v10 last series. Here is brief summary. > > Each channel device has a sysfs entry named chid. > What: /sys/devices/platform/hidma-*/chid > + /sys/devices/platform/QCOM8061:*/chid > > > Each management object has one priority and weight file per channel. > +What: /sys/devices/platform/hidma-mgmt*/chanops/chan*/priority > + /sys/devices/platform/QCOM8060:*/chanops/chan*/priority > > Suppose you want to change the priority of a channel you assigned to guess, > the userspace application goes and reads the chid value of the channel. > > Then goes to chanops/chan/ directory and can change priority and weight > parameters here. > > Here is how the directory looks like. QCOM8060:00 is a management object. > QCOM8061:0x are the channel objects. > > /sys/devices/platform/QCOM8060:00# ls > QCOM8061:00 > QCOM8061:01 > QCOM8061:02 > QCOM8061:03 > QCOM8061:04 > QCOM8061:05 > chanops > > > > > Did this answer your question? I'm capturing all the questions and answers as FAQ into the cover letter as I keep repeating myself for every single reviewer. Besides from the "lack of documentation", is there any code related change you'd like to discuss in the series. -- Sinan Kaya Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project