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From: George Shore <george-ofzTHo7+kyPpQY4QmZNtDQ@public.gmane.org>
To: spi-devel-list
	<spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>,
	Grant Likely
	<grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>,
	David Brownell
	<dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
Cc: George Shore <george-ofzTHo7+kyPpQY4QmZNtDQ@public.gmane.org>
Subject: [PATCH 4/5] spi/dw_spi.c: remove conditional from 'poll_transfer'.
Date: Thu, 21 Jan 2010 11:40:51 +0000	[thread overview]
Message-ID: <1264074052-2214-4-git-send-email-george@georgeshore.com> (raw)
In-Reply-To: <1264074052-2214-1-git-send-email-george-ofzTHo7+kyPpQY4QmZNtDQ@public.gmane.org>

The 'poll_transfer' function employs a conditional to test whether the
transmit buffer is valid; in doing so, on a receive operation no data is
clocked out, thus no data is clocked in and ultimately errors appear.

This removes the conditional as the transmit function will be set to a null
writer when the transmit buffer is invalid, allowing the driver to clock 0x00
out to the device to receive data from the device.

Signed-off-by: George Shore <george-ofzTHo7+kyPpQY4QmZNtDQ@public.gmane.org>
---
 drivers/spi/dw_spi.c |    7 ++-----
 1 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
index 01292da..4f91554 100644
--- a/drivers/spi/dw_spi.c
+++ b/drivers/spi/dw_spi.c
@@ -408,12 +408,9 @@ static irqreturn_t dw_spi_irq(int irq, void *dev_id)
 /* Must be called inside pump_transfers() */
 static void poll_transfer(struct dw_spi *dws)
 {
-	if (dws->tx) {
-		while (dws->write(dws))
-			dws->read(dws);
-	}
+	while (dws->write(dws))
+		dws->read(dws);
 
-	dws->read(dws);
 	transfer_complete(dws);
 }
 
-- 
1.6.6.264.gd0743


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  parent reply	other threads:[~2010-01-21 11:40 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-21 11:40 [PATCH 1/5] include/linux/spi/dw_spi.h: enable platform specific chipselect George Shore
     [not found] ` <1264074052-2214-1-git-send-email-george-ofzTHo7+kyPpQY4QmZNtDQ@public.gmane.org>
2010-01-21 11:40   ` [PATCH 2/5] spi/dw_spi: add return value to empty mrst_spi_debugfs_init() George Shore
2010-01-21 11:40   ` [PATCH 3/5] spi/dw_spi: fixed a spelling typo in a warning message George Shore
2010-01-21 11:40   ` George Shore [this message]
2010-01-21 11:40   ` [PATCH 5/5] spi/dw_spi.c: conditional transfer mode changes George Shore
2010-01-21 14:49   ` [PATCH 1/5] include/linux/spi/dw_spi.h: enable platform specific chipselect Grant Likely

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