From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Y86W4-0005Cx-UP for barebox@lists.infradead.org; Mon, 05 Jan 2015 12:12:14 +0000 Date: Mon, 5 Jan 2015 13:11:50 +0100 From: Sascha Hauer Message-ID: <20150105121150.GC4544@pengutronix.de> References: <1420142663-6243-1-git-send-email-robert.jarzmik@free.fr> <1420142663-6243-2-git-send-email-robert.jarzmik@free.fr> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1420142663-6243-2-git-send-email-robert.jarzmik@free.fr> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH] net: smc1111: fix memory congestions To: Robert Jarzmik Cc: barebox@lists.infradead.org On Thu, Jan 01, 2015 at 09:04:22PM +0100, Robert Jarzmik wrote: > As the SMC1111 has a shared pool of 2k memory buckets for both > transmission and reception, and as there are variants which have as few > as 4 buckets in total, the memory pool can be hogged by unclaimed > receptions, and impeed any further transmission. > > This happens on the zylonite pxa board, where 4 packets, most probably > icmp and arp, fill the 4 buckets, preventing any further ethernet > transmission, and stalling the driver. > > The fix is rather rough : whenever all the buckets are filled by > reception packets, and if a transmission is required, the transmission > code path will empty up all received packets. I don't know the hardware (not anymore, fortunately ;), but isn't it possible to dedicate one bucket for transmitting only, so that it will never be occupied by a received packet? Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox