From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH V2 1/2] ARM: OMAP2+: DMA: remove requirement of irq for platform-dma driver Date: Mon, 21 Jul 2014 23:37:40 -0700 Message-ID: <20140722063740.GG18374@atomide.com> References: <1402573523-13814-1-git-send-email-r.sricharan@ti.com> <1402573523-13814-2-git-send-email-r.sricharan@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-03-ewr.mailhop.org ([204.13.248.66]:47627 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751302AbaGVGjF (ORCPT ); Tue, 22 Jul 2014 02:39:05 -0400 Content-Disposition: inline In-Reply-To: <1402573523-13814-2-git-send-email-r.sricharan@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Sricharan R Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, santosh.shilimkar@ti.com, nm@ti.com, rnayak@ti.com, linux@arm.linux.org.uk * Sricharan R [140612 04:48]: > From: Nishanth Menon > > we have currently 2 DMA drivers that try to co-exist. > drivers/dma/omap-dma.c which registers it's own IRQ and is device tree > aware and uses arch/arm/plat-omap/dma.c instance created by > arch/arm/mach-omap2/dma.c to maintain channel usage (omap_request_dma). > > Currently both try to register interrupts and mach-omap2/plat-omap dma.c > attempts to use the IRQ number registered by hwmod to register it's own > interrupt handler. > > Now, there is no reasonable way of static allocating DMA irq in GIC > SPI when we use crossbar. However, since the dma_chan structure is > freed as a result of IRQ not being present due to devm allocation, > maintaining information of channel by platform code fails at a later > point in time when that region of memory is reused. > > So, if hwmod does not indicate an IRQ number, then, assume that > dma-engine will take care of the interrupt handling. Looks OK to me, applying both into omap-for-v3.17/soc thanks. Regards, Tony