From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752479AbcHIGLb (ORCPT ); Tue, 9 Aug 2016 02:11:31 -0400 Received: from mail1.bemta3.messagelabs.com ([195.245.230.176]:50099 "EHLO mail1.bemta3.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751373AbcHIGL3 (ORCPT ); Tue, 9 Aug 2016 02:11:29 -0400 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprBKsWRWlGSWpSXmKPExsUS8J9toi53ycp wg2nd3Barru1gtJj2XM9izvkWFovHXTNYLVZ9n8pscXnXHDaL9YumsFgcWyBmsfTeTlYHTo8t K28yeeycdZfd4+Ol24we/X8NPDafrvb4vEnOo//SQ8YA9ijWzLyk/IoE1ozmvavZC5q4KvY/W 8PcwHiNvYuRi0NIoIFR4tnfXSxdjBwcEgJ+Evc3SELE5zFKHHl+CyjOycEioCJx+eBRNhCbTU BH4lx7MyuILSJgKLHqcQ8TSAOzwCdGiQXHDzCCJIQFQiT6T15gBrF5gRr6v9xjhZi6lVHif08 /E0RCUOLkzCdgG5iBihbs/sQGcgWzgLTE8n8cIGFOATuJdxcbWEHCokBHvDpYDxIWElCS+Pyi D2y8hIC8xN6+xWwQ98dJfLljCmFaS0zcnDiBUXgWklWzkKyahbBqASPzKkaN4tSistQiXSNDv aSizPSMktzEzBxdQwNjvdzU4uLE9NScxKRiveT83E2MwBirZ2Bg3MHYs9fvEKMkB5OSKG+75c pwIb6k/JTKjMTijPii0pzU4kOMMhwcShK8ssVAOcGi1PTUirTMHGC0w6QlOHiURHgfFAGleYs LEnOLM9MhUqcYFaXEeTeCJARAEhmleXBtsARziVFWSpiXkYGBQYinILUoN7MEVf4VozgHo5Iw 7wWQKTyZeSVw018BLWYCWpykugJkcUkiQkqqgXFa8u+HB4TPeK64+t6Z+b7nkROv/pXZLt7sd aNyk/O66Dzhp3vjV0yuFfr9ebkv72YXIbs9T9J6Jc1F/3PK+3orHIi4u4bL8bvziqcVrSePzt sn37pdeZr8m62rNO9X3orYZFEaf3Gitlr6MuuwN3Z/TBNFd2VsamFwnf9HfEF/67ZlJm6xDzq UWIozEg21mIuKEwF7ScfIKwMAAA== X-Env-Sender: Andreas.Werner@men.de X-Msg-Ref: server-6.tower-38.messagelabs.com!1470723082!55969771!1 X-Originating-IP: [80.255.6.145] X-StarScan-Received: X-StarScan-Version: 8.77; banners=-,-,- X-VirusChecked: Checked X-PGP-Universal: processed; by keys.men.de on Tue, 09 Aug 2016 08:11:23 +0200 Date: Tue, 9 Aug 2016 08:11:21 +0200 From: Andreas Werner To: Benjamin Poirier CC: Andreas Werner , , , , , , , , Subject: Re: [PATCH RESEND] net: can: Introduce MEN 16Z192-00 CAN controller driver Message-ID: <20160809061121.GD1733@awelinux> References: <20160726091555.GA26227@awelinux> <20160808035814.ulqx4hnbtkkd2iko@f1.synalogic.ca> <20160808072620.GA5749@awelinux> <20160809032355.fzbdpudsqg2bdn27@f1.synalogic.ca> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20160809032355.fzbdpudsqg2bdn27@f1.synalogic.ca> User-Agent: Mutt/1.5.24 (2015-08-30) X-Originating-IP: [192.1.1.170] X-ClientProxiedBy: MEN-EX01.intra.men.de (192.168.1.1) To MEN-EX01.intra.men.de (192.168.1.1) X-EXCLAIMER-MD-CONFIG: e4841e51-7998-49c0-ba41-8b8a0e2d8962 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 08, 2016 at 08:23:55PM -0700, Benjamin Poirier wrote: > On 2016/08/08 09:26, Andreas Werner wrote: > [...] > > > > + > > > > + if (cf->can_dlc > 0) > > > > + data[0] = be32_to_cpup((__be32 *)(cf->data)); > > > > + if (cf->can_dlc > 3) > > > > + data[1] = be32_to_cpup((__be32 *)(cf->data + 4)); > > > > + > > > > + writel(id, &cf_buf->can_id); > > > > + writel(cf->can_dlc, &cf_buf->length); > > > > + > > > > + if (!(cf->can_id & CAN_RTR_FLAG)) { > > > > + writel(data[0], &cf_buf->data[0]); > > > > + writel(data[1], &cf_buf->data[1]); > > > > + > > > > + stats->tx_bytes += cf->can_dlc; > > > > + } > > > > + > > > > + /* be sure everything is written to the > > > > + * device before acknowledge the data. > > > > + */ > > > > + mmiowb(); > > > > + > > > > + /* trigger the transmission */ > > > > + men_z192_ack_tx_pkg(priv, 1); > > > > + > > > > + stats->tx_packets++; > > > > + > > > > + kfree_skb(skb); > > > > > > What prevents the skb data to be freed/reused before the device has > > > accessed it? > > I'm sorry, I hadn't realized that all of the data (all 8 bytes of it!) > is written directly to the device. I was thinking about ethernet devices > that dma packet data. Ah ok :-) I thought you just want me to free the skb earlier. Regards Andy