From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] OMAP2/3/4: DMA: reset controller during init Date: Mon, 3 May 2010 09:36:01 -0700 Message-ID: <20100503163600.GQ29604@atomide.com> References: <1272891357-27400-1-git-send-email-ext-mika.1.westerberg@nokia.com> <87zl0h6khl.fsf@deeprootsystems.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:59367 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758812Ab0ECQgJ (ORCPT ); Mon, 3 May 2010 12:36:09 -0400 Content-Disposition: inline In-Reply-To: <87zl0h6khl.fsf@deeprootsystems.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Kevin Hilman Cc: Mika Westerberg , linux-omap@vger.kernel.org * Kevin Hilman [100503 08:58]: > Mika Westerberg writes: > > > If we are softbooting another kernel using kexec, DMA controller state is not > > known when we are performing omap_init_dma(). It is possible that some DMA > > channels are already active. For example after kexec we get: > > > > <4>IRQ 0020 for non-allocated DMAchannel 5 > > <4>IRQ 0020 for non-allocated DMAchannel 5 > > <4>IRQ 0020 for non-allocated DMAchannel 5 > > <4>IRQ 0020 for non-allocated DMAchannel 5 > > <4>IRQ 0020 for non-allocated DMAchannel 5 > > > > To prevent any weird things happening, we perform soft reset for the controller > > and disable all per channel interrupts. > > > > Signed-off-by: Mika Westerberg > > This is a good fix, but we get reset of DMA (and all other blocks) for > free when switching to hwmod. Here's a good reason to convert DMA > to hwmod. Hmm, do we have existing DMA hwmod patches somewhere that work on all omaps? Tony