From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934112AbYBGA1n (ORCPT ); Wed, 6 Feb 2008 19:27:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760032AbYBFX74 (ORCPT ); Wed, 6 Feb 2008 18:59:56 -0500 Received: from mx1.suse.de ([195.135.220.2]:46580 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932653AbYBFX7y (ORCPT ); Wed, 6 Feb 2008 18:59:54 -0500 Date: Wed, 6 Feb 2008 15:54:17 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org, torvalds@linux-foundation.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, dbrownell@users.sourceforge.net, kalle.valo@nokia.com Subject: [patch 64/73] spi: omap2_mcspi PIO RX fix Message-ID: <20080206235417.GM13121@suse.de> References: <20080206234302.769849277@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="spi-omap2_mcspi-pio-rx-fix.patch" In-Reply-To: <20080206235015.GA13121@suse.de> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.23-stable review patch. If anyone has any objections, please let us know. ------------------ From: Kalle Valo patch feed9bab7b14b77be8d796bcee95e2343fb82955 in mainline. Before transmission of the last word in PIO RX_ONLY mode rx+tx mode is enabled: /* prevent last RX_ONLY read from triggering * more word i/o: switch to rx+tx */ if (c == 0 && tx == NULL) mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l); But because c is decremented after the test, c will never be zero and rx+tx will not be enabled. This breaks RX_ONLY mode PIO transfers. Fix it by decrementing c in the beginning of the various I/O loops. Signed-off-by: Kalle Valo Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/spi/omap2_mcspi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -350,6 +350,7 @@ omap2_mcspi_txrx_pio(struct spi_device * tx = xfer->tx_buf; do { + c -= 1; if (tx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) { @@ -380,7 +381,6 @@ omap2_mcspi_txrx_pio(struct spi_device * word_len, *(rx - 1)); #endif } - c -= 1; } while (c); } else if (word_len <= 16) { u16 *rx; @@ -389,6 +389,7 @@ omap2_mcspi_txrx_pio(struct spi_device * rx = xfer->rx_buf; tx = xfer->tx_buf; do { + c -= 2; if (tx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) { @@ -419,7 +420,6 @@ omap2_mcspi_txrx_pio(struct spi_device * word_len, *(rx - 1)); #endif } - c -= 2; } while (c); } else if (word_len <= 32) { u32 *rx; @@ -428,6 +428,7 @@ omap2_mcspi_txrx_pio(struct spi_device * rx = xfer->rx_buf; tx = xfer->tx_buf; do { + c -= 4; if (tx != NULL) { if (mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS) < 0) { @@ -458,7 +459,6 @@ omap2_mcspi_txrx_pio(struct spi_device * word_len, *(rx - 1)); #endif } - c -= 4; } while (c); } --