spi: xilinx: Move timeout calculation out of the loop

Timeout calculation should be out of the data loop. This patch increase spi bandwidth for 30%. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>

spi: xilinx: Move timeout calculation out of the loop
Timeout calculation should be out of the data loop. This patch increase spi bandwidth for 30%. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Michal Simek · Jagannadha Sutradharudu Teki
1 parent 22a240c32c
Showing 1 changed file with 5 additions and 3 deletions Side-by-side Diff
drivers/spi/xilinx_spi.c
@@ -149,6 +149,7 @@
 	const unsigned char *txp = dout;
 	unsigned char *rxp = din;
 	unsigned rxecount = 17;	/* max. 16 elements in FIFO, leftover 1 */
+	unsigned global_timeout;
  
 	debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
 		slave->bus, slave->cs, bitlen, bytes, flags);
  
@@ -176,11 +177,12 @@
 	if (flags & SPI_XFER_BEGIN)
 		spi_cs_activate(slave);
  
-	while (bytes--) {
-		unsigned timeout = /* at least 1usec or greater, leftover 1 */
-			xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
+	/* at least 1usec or greater, leftover 1 */
+	global_timeout = xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
 			(XILSPI_MAX_XFER_BITS * 1000000 / xilspi->freq) + 1;
  
+	while (bytes--) {
+		unsigned timeout = global_timeout;
 		/* get Tx element from data out buffer and count up */
 		unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL;
 		debug("%s: tx:%x ", __func__, d);
...	...	@@ -149,6 +149,7 @@
149	149	const unsigned char *txp = dout;
150	150	unsigned char *rxp = din;
151	151	unsigned rxecount = 17; /* max. 16 elements in FIFO, leftover 1 */
	152	+ unsigned global_timeout;
152	153
153	154	debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
154	155	slave->bus, slave->cs, bitlen, bytes, flags);
155	156
...	...	@@ -176,11 +177,12 @@
176	177	if (flags & SPI_XFER_BEGIN)
177	178	spi_cs_activate(slave);
178	179
179		- while (bytes--) {
180		- unsigned timeout = /* at least 1usec or greater, leftover 1 */
181		- xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
	180	+ /* at least 1usec or greater, leftover 1 */
	181	+ global_timeout = xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
182	182	(XILSPI_MAX_XFER_BITS * 1000000 / xilspi->freq) + 1;
183	183
	184	+ while (bytes--) {
	185	+ unsigned timeout = global_timeout;
184	186	/* get Tx element from data out buffer and count up */
185	187	unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL;
186	188	debug("%s: tx:%x ", __func__, d);