From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gilad Avidov Subject: Re: [PATCH] spmi-pmic-arb: add irq tracepoints to the pmic-arb driver Date: Thu, 28 May 2015 17:02:50 -0600 Message-ID: <20150528170250.16027406@gavidov-lnx.qualcomm.com> References: <1432683555-4644-1-git-send-email-ankgupta@codeaurora.org> <5565056D.4050200@codeaurora.org> <4da368f6f34fc07eff97ddc3dfbced2c.squirrel@www.codeaurora.org> <20150527200629.GB24204@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150527200629.GB24204@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: Stephen Boyd Cc: Ankit Gupta , sdharia@codeaurora.org, ivan.ivanov@linaro.org, svarbanov@mm-sol.com, rostedt@goodmis.org, linux-arm-msm@vger.kernel.org, gregkh@linuxfoundation.org, collinsd@codeaurora.org, osvaldob@codeaurora.org, linux-kernel@vger.kernel.org, mlocke@codeaurora.org, galak@codeaurora.org, agross@codeaurora.org List-Id: linux-arm-msm@vger.kernel.org On Wed, 27 May 2015 13:06:29 -0700 Stephen Boyd wrote: > On 05/27, Ankit Gupta wrote: > > > > > > How is this any better than irq tracepoints that we already have > > > for generic irqs? > > > > > It is better than generic irq tracepoints because it provides bus > > specific information (sid and address(pid) of slave write), driver > > specific information (apid (pmic-peripheral) and func_num) and > > statistics (apid range). > > Recall that *slave* read/write cannot be traced by the spmi > > framework ftrace. > > > > Don't we already get all this information based on how we map > interrupts to devices in DT? It feels to me that the same > argument here could be applied to all the random gpio expanders > and chained interrupt controllers that we support in the kernel. > We don't. We could get the same information if we had the irq-domain and hw-irq 32bit value. While these values are available from /proc/interrupt, they are not available from the irq event tracing. This patch traces spmi slave-originated events. If we had one such slave we could cross information from both sources to filter the trace events. However, we have hundreds of transaction-capable spmi slaves. Thanks, Gilad