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From: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
To: "Mark Brown" <broonie@kernel.org>,
	"Michal Simek" <michal.simek@xilinx.com>,
	"Sören Brinkmann" <soren.brinkmann@xilinx.com>,
	linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Subject: [PATCH 03/18] spi/xilinx: Simplify data read from the Rx FIFO
Date: Fri, 23 Jan 2015 17:08:35 +0100	[thread overview]
Message-ID: <1422029330-10971-4-git-send-email-ricardo.ribalda@gmail.com> (raw)
In-Reply-To: <1422029330-10971-1-git-send-email-ricardo.ribalda@gmail.com>

The number of words in the read buffer will be exactly the same as the
number of words written on write buffer, once the transaction has
finished.

Instead of cheking the rx_empty flags for every word simply save the
number of words written by fill_tx_fifo.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/spi/spi-xilinx.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c
index e1d9a20..416b227 100644
--- a/drivers/spi/spi-xilinx.c
+++ b/drivers/spi/spi-xilinx.c
@@ -221,9 +221,10 @@ static int xilinx_spi_setup_transfer(struct spi_device *spi,
 	return 0;
 }
 
-static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi)
+static int xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi)
 {
 	u8 sr;
+	int n_words = 0;
 
 	/* Fill the Tx FIFO with as many bytes as possible */
 	sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
@@ -234,7 +235,10 @@ static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi)
 			xspi->write_fn(0, xspi->regs + XSPI_TXD_OFFSET);
 		xspi->remaining_bytes -= xspi->bits_per_word / 8;
 		sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
+		n_words++;
 	}
+
+	return n_words;
 }
 
 static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
@@ -259,9 +263,9 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
 
 	for (;;) {
 		u16 cr;
-		u8 sr;
+		int n_words;
 
-		xilinx_spi_fill_tx_fifo(xspi);
+		n_words = xilinx_spi_fill_tx_fifo(xspi);
 
 		/* Start the transfer by not inhibiting the transmitter any
 		 * longer
@@ -282,11 +286,8 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
 			       xspi->regs + XSPI_CR_OFFSET);
 
 		/* Read out all the data from the Rx FIFO */
-		sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
-		while ((sr & XSPI_SR_RX_EMPTY_MASK) == 0) {
+		while (n_words--)
 			xspi->rx_fn(xspi);
-			sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
-		}
 
 		/* See if there is more data to send */
 		if (xspi->remaining_bytes <= 0)
-- 
2.1.4


  parent reply	other threads:[~2015-01-23 16:14 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-23 16:08 [PATCH 00/18] spi/xilinx: Speed-up Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 01/18] spi/xilinx: Support for spi mode LSB_FIRST Ricardo Ribalda Delgado
2015-01-26 19:23   ` Mark Brown
2015-01-23 16:08 ` [PATCH 02/18] spi/xilinx: Support for spi mode LOOP Ricardo Ribalda Delgado
2015-01-26 19:23   ` Mark Brown
2015-01-23 16:08 ` Ricardo Ribalda Delgado [this message]
2015-01-27 17:25   ` [PATCH 03/18] spi/xilinx: Simplify data read from the Rx FIFO Mark Brown
2015-01-23 16:08 ` [PATCH 04/18] spi-xilinx: Simplify spi_fill_tx_fifo Ricardo Ribalda Delgado
2015-01-26 23:54   ` Mark Brown
2015-01-23 16:08 ` [PATCH 05/18] spi/xilinx: Leave the IRQ always enabled Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 06/18] spi/xilinx: Code cleanup Ricardo Ribalda Delgado
2015-01-27  0:05   ` Mark Brown
2015-01-23 16:08 ` [PATCH 07/18] spi/xilinx: Use cached value of register Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 08/18] spi/xilinx: Support cores with no interrupt Ricardo Ribalda Delgado
2015-01-27  0:04   ` Mark Brown
2015-01-27 19:05     ` Ricardo Ribalda Delgado
2015-01-27 19:49       ` Mark Brown
2015-01-27 19:56         ` Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 09/18] spi/xilinx: Do not inhibit transmission in polling mode Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 10/18] spi/xilinx: Support for spi mode CS_HIGH Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 11/18] spi/xilinx: Remove rx_fn and tx_fn pointer Ricardo Ribalda Delgado
2015-01-27  0:09   ` Mark Brown
2015-01-27 10:00     ` Ricardo Ribalda Delgado
2015-01-27 15:42       ` Joe Perches
2015-01-27 19:07         ` Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 12/18] spi/xilinx: Make spi_tx and spi_rx simmetric Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 13/18] spi/xilinx: Convert remainding_bytes in remaining words Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 14/18] spi/xilinx: Convert bits_per_word in bytes_per_word Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 15/18] spi/xilinx: Remove iowrite/ioread wrappers Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 16/18] spi/xilinx: Reset core before buffer_size detection Ricardo Ribalda Delgado
2015-01-27  0:11   ` Mark Brown
2015-01-23 16:08 ` [PATCH 17/18] spi/xilinx: Remove remaining_words driver data variable Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 18/18] spi/xilinx: Check number of slaves range Ricardo Ribalda Delgado
2015-01-27  0:14 ` [PATCH 00/18] spi/xilinx: Speed-up Mark Brown
2015-01-27 10:17   ` Ricardo Ribalda Delgado
2015-01-27 11:59     ` Mark Brown

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