Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934109Ab0D3Sfl (ORCPT ); Fri, 30 Apr 2010 14:35:41 -0400 Received: from fg-out-1718.google.com ([72.14.220.157]:17305 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934087Ab0D3SfW (ORCPT ); Fri, 30 Apr 2010 14:35:22 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:reply-to:to:cc:in-reply-to:references:content-type :date:message-id:mime-version:x-mailer:content-transfer-encoding; b=Kiibzb75PsGOGkJHcIC3Vu8wldtHaKQh34zLkdrsAOHNs6TSspf6DLcMYXiKWfimoI l3OBtt3+XjLMqSjJAjx6+Z2WTWLgJMDzg7kWpsuL5mGjAJhNoGcTc1aOify8luooig+P JZ+21/++66btFS+hVxd4zuS/uzgjs4RTUC/b0= Subject: RE: [PATCH] sst25l.c: simplify reading the device ManID/DevID From: Artem Bityutskiy Reply-To: dedekind1@gmail.com To: H Hartley Sweeten Cc: David Woodhouse , "ryan@bluewatersys.com" , "andre@bluewatersys.com" , "linux-mtd@lists.infradead.org" , Linux Kernel In-Reply-To: <0D753D10438DA54287A00B0270842697636E305B2F@AUSP01VMBX24.collaborationhost.net> References: <0D753D10438DA54287A00B0270842697636D85BD7C@AUSP01VMBX24.collaborationhost.net> <1272519398.7750.67.camel@localhost> <0D753D10438DA54287A00B0270842697636E305B2F@AUSP01VMBX24.collaborationhost.net> Content-Type: text/plain; charset="UTF-8" Date: Thu, 29 Apr 2010 21:07:46 +0300 Message-Id: <1272564466.2593.3.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 (2.26.3-1.fc11) Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2046 Lines: 45 On Thu, 2010-04-29 at 12:11 -0500, H Hartley Sweeten wrote: > On Wednesday, April 28, 2010 10:37 PM, Artem Bityutskiy wrote: > > On Tue, 2010-04-20 at 18:17 -0500, H Hartley Sweeten wrote: > >> The Read-ID command will continuously output the Manufacture ID and Device ID > >> until the command is terminated by a low to high transition on the CE# pin. > >> We can take advantage of this in the sst25l_match_device routine by reading > >> both bytes in one spi_write_then_read transaction. > >> > >> Signed-off-by: H Hartley Sweeten > >> Cc: David Woodhouse > >> Cc: Andre Renaud > >> Cc: Ryan Mallon > > > > Pushed to l2-mtd-2.6.git / dunno. > > Artem, > > I have discovered that the Read-Status-Register command has the same problem. > With the SST25L SPI flash chips, if the chip enable is deasserted after sending > a command that command will get aborted. > > I ran across this while testing a new spi master driver for the ep93xx on an > EDB9307A dev board. That board uses the processors SFRMOUT signal as part of > the chip select logic. Unfortunately the ep93xx only asserts the SFRMOUT > signal as long as the spi transmit fifo contains data. As soon as the last > bit is clocked into the receive fifo it gets deasserted. Many of the other > ep93xx based boards have that same issue. > > I have an updated patch that changes both of these into one synchronous message > which fixes the sst25l_status and sst25l_match_device functions. These changes > should be transparent to any users of this driver. > > Could you drop the current patch and I will submit the updated one for review? Of course, just send it. -- Best Regards, Artem Bityutskiy (Артём Битюцкий) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/