From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751477AbbKCHo2 (ORCPT ); Tue, 3 Nov 2015 02:44:28 -0500 Received: from mail-wm0-f42.google.com ([74.125.82.42]:38003 "EHLO mail-wm0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750807AbbKCHoY (ORCPT ); Tue, 3 Nov 2015 02:44:24 -0500 MIME-Version: 1.0 In-Reply-To: <20151103063009.GT21326@localhost> References: <1446444460-21600-1-git-send-email-okaya@codeaurora.org> <1446444460-21600-3-git-send-email-okaya@codeaurora.org> <20151103041528.GS21326@localhost> <5638359D.9080507@codeaurora.org> <20151103063009.GT21326@localhost> Date: Mon, 2 Nov 2015 23:44:23 -0800 Message-ID: Subject: Re: [PATCH V2 2/3] dmaselftest: add memcpy selftest support functions From: Dan Williams To: Vinod Koul Cc: Sinan Kaya , "dmaengine@vger.kernel.org" , timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 2, 2015 at 10:30 PM, Vinod Koul wrote: > On Mon, Nov 02, 2015 at 11:18:37PM -0500, Sinan Kaya wrote: >> >> >> On 11/2/2015 11:15 PM, Vinod Koul wrote: >> >On Mon, Nov 02, 2015 at 01:07:38AM -0500, Sinan Kaya wrote: >> >>This patch adds supporting utility functions >> >>for selftest. The intention is to share the self >> >>test code between different drivers. >> >> >> >>Supported test cases include: >> >>1. dma_map_single >> >>2. streaming DMA >> >>3. coherent DMA >> >>4. scatter-gather DMA >> > >> >This seems quite similar to dmatest, any reason why you cannot use/enhance >> >that? >> > >> Dmatest is a standalone kernel module intended for stress testing >> DMA engines from userspace with N number of threads and M size >> combinations etc. >> >> This one; on the other hand, is selftest to verify hardware is >> working as expected during power up. >> >> Almost all DMA engine drivers come with some sort of selftest code >> called from probe. I followed the same design pattern. > > which ones ? > >> >> I think the goal is to remove the duplicate self test code in all >> drivers over time. > > and what prevents us from having common selftest plus dmatest code. Most of > the code here to do selftest is _same_ dmaengine routine code used in > dmatest > > We can have common code which is used for dmatest as well as selftest. I do > not want to see same code duplicated.. Originally ioatdma and iop-adma had local self tests before Haavard created dmatest. I agree having the drivers also do a test each boot is redundant, but then again dmatest is not automatic and I saw the local self test catch an interrupt setup regression. Maybe you could arrange for drivers to do a quick autorun through dmatest on load if dmatest is enabled, but otherwise load without testing? Just my 2 cents from a dmaengine spectator.