From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: omap-serial: transmission of x-char with DMA (and other issues) Date: Fri, 13 Apr 2012 11:41:11 +0100 Message-ID: <20120413104111.GF25053@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:54204 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751101Ab2DMKlQ (ORCPT ); Fri, 13 Apr 2012 06:41:16 -0400 Content-Disposition: inline Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-omap@vger.kernel.org, linux-serial@vger.kernel.org Can someone tell me how this works with the current omap-serial driver please? It looks to me like this has been broken when DMA support was added to the driver. Moreover, please look at the probe function error paths. They seem to be lacking any kind of realistic cleanup, so are a potential memory leak. Then there's the issue of fiddling with the xmit buffer so that it's using coherent memory in the startup and shutdown functions (why? when other serial drivers cope just fine without doing this). If we want to use DMA coherent memory there, there should be a clean way to do this, rather than going behind the upper layers.