From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753614AbcBIHUN (ORCPT ); Tue, 9 Feb 2016 02:20:13 -0500 Received: from smtp06.smtpout.orange.fr ([80.12.242.128]:51372 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750781AbcBIHUL (ORCPT ); Tue, 9 Feb 2016 02:20:11 -0500 X-ME-Helo: belgarion X-ME-Auth: amFyem1pay5yb2JlcnRAb3JhbmdlLmZy X-ME-Date: Tue, 09 Feb 2016 08:20:09 +0100 X-ME-IP: 109.222.219.121 From: Robert Jarzmik To: Vinod Koul Cc: Daniel Mack , Haojian Zhuang , linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] dmaengine: pxa_dma: fix the maximum requestor line References: <1454941131-12308-1-git-send-email-robert.jarzmik@free.fr> <20160209033646.GK19598@localhost> X-URL: http://belgarath.falguerolles.org/ Date: Tue, 09 Feb 2016 08:20:05 +0100 In-Reply-To: <20160209033646.GK19598@localhost> (Vinod Koul's message of "Tue, 9 Feb 2016 09:06:46 +0530") Message-ID: <878u2u2vve.fsf@belgarion.home> User-Agent: Gnus/5.130008 (Ma Gnus v0.8) Emacs/24.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vinod Koul writes: > On Mon, Feb 08, 2016 at 03:18:51PM +0100, Robert Jarzmik wrote: >> The current number of requestor lines is limited to 31. This was an >> error of a previous commit, as this number is platform dependent, and is >> actually : >> - for pxa25x: 40 requestor lines >> - for pxa27x: 74 requestor lines >> - for pxa3xx: 100 requestor lines >> >> As the driver doesn't need to know the exact number, but only an > > and why would that be a good assumption? Well, the driver doesn't use the exact value. Would that be 128, 1000 or 10000, it wouldn't change its behavior. The clients either pass -1UL (ie. no flow control) or a requestor line number. > Btw shouldn't this data come from DT? It can if you wish, but in this case I must amend the platform data case too, ie mmp_dma_platdata. And this has an impact on MMP architecture. I'd rather have the simpler approach unless you really want the exact number of requestor lines to be passed in platform_data+DT. Cheers. -- Robert