Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762284AbYGaC52 (ORCPT ); Wed, 30 Jul 2008 22:57:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761116AbYGaCu7 (ORCPT ); Wed, 30 Jul 2008 22:50:59 -0400 Received: from SpacedOut.fries.net ([67.64.210.234]:55961 "EHLO SpacedOut.fries.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761047AbYGaCu6 (ORCPT ); Wed, 30 Jul 2008 22:50:58 -0400 Date: Wed, 30 Jul 2008 21:50:02 -0500 From: David Fries To: Andrew Morton Cc: Evgeniy Polyakov , linux-kernel@vger.kernel.org Subject: [PATCH 21/30] W1: ds2490.c ds_write_bit, grouping error, disable readback Message-ID: <20080731025002.GV12181@spacedout.fries.net> References: <20080729020433.GA24424@spacedout.fries.net> <20080729161356.2de456fb.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080729161356.2de456fb.akpm@linux-foundation.org> User-Agent: Mutt/1.5.4i X-Greylist: Sender is SPF-compliant, not delayed by milter-greylist-3.0 (SpacedOut.fries.net [127.0.0.1]); Wed, 30 Jul 2008 21:50:02 -0500 (CDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1381 Lines: 37 ds_write_bit doesn't read the input buffer, so add COMM_ICP and a comment that it will no longer generate a read back data byte. If there is an extra data byte later on then it will cause an error and discard what data was there. Corrected operator ordering for ds_send_control. Signed-off-by: David Fries Signed-off-by: Evgeniy Polyakov --- drivers/w1/masters/ds2490.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c index 6b188e8..6fabf58 100644 --- a/drivers/w1/masters/ds2490.c +++ b/drivers/w1/masters/ds2490.c @@ -525,7 +525,12 @@ static int ds_write_bit(struct ds_device *dev, u8 bit) int err; struct ds_status st; - err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit) ? COMM_D : 0, 0); + /* Set COMM_ICP to write without a readback. Note, this will + * produce one time slot, a down followed by an up with COMM_D + * only determing the timing. + */ + err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP | + (bit ? COMM_D : 0), 0); if (err) return err; -- 1.4.4.4 -- 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/