[8/9] spi/pxa2xx: Modify RX-Tresh instead of busy-loop for the remaining RX bytes.

Commit Message

Sebastian Andrzej Siewior Nov. 24, 2010, 11:13 a.m. UTC

None

Patch

diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c
index d77e47f..5c8c6e3 100644
--- a/drivers/spi/pxa2xx_spi.c
+++ b/drivers/spi/pxa2xx_spi.c
@@ -660,13 +660,25 @@  static irqreturn_t dma_transfer(struct driver_data *drv_data)
 	return IRQ_NONE;
 }
 
+static void reset_sccr1(struct driver_data *drv_data)
+{
+	void __iomem *reg = drv_data->ioaddr;
+	struct chip_data *chip = drv_data->cur_chip;
+	u32 sccr1_reg;
+
+	sccr1_reg = read_SSCR1(reg) & ~drv_data->int_cr1;
+	sccr1_reg &= ~SSCR1_RFT;
+	sccr1_reg |= chip->threshold;
+	write_SSCR1(sccr1_reg, reg);
+}
+
 static void int_error_stop(struct driver_data *drv_data, const char* msg)
 {
 	void __iomem *reg = drv_data->ioaddr;
 
 	/* Stop and reset SSP */
 	write_SSSR_CS(drv_data, drv_data->clear_sr);
-	write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
+	reset_sccr1(drv_data);
 	if (!pxa25x_ssp_comp(drv_data))
 		write_SSTO(0, reg);
 	flush(drv_data);
@@ -684,7 +696,7 @@  static void int_transfer_complete(struct driver_data *drv_data)
 
 	/* Stop SSP */
 	write_SSSR_CS(drv_data, drv_data->clear_sr);
-	write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
+	reset_sccr1(drv_data);
 	if (!pxa25x_ssp_comp(drv_data))
 		write_SSTO(0, reg);
 
@@ -739,24 +751,34 @@  static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 	}
 
 	if (drv_data->tx == drv_data->tx_end) {
-		write_SSCR1(read_SSCR1(reg) & ~SSCR1_TIE, reg);
-		/* PXA25x_SSP has no timeout, read trailing bytes */
+		u32 bytes_left;
+		u32 sccr1_reg;
+
+		sccr1_reg = read_SSCR1(reg);
+		sccr1_reg &= ~SSCR1_TIE;
+
+		/*
+		 * PXA25x_SSP has no timeout, set up rx threshould for the
+		 * remaing RX bytes.
+		 */
 		if (pxa25x_ssp_comp(drv_data)) {
-			if (!wait_ssp_rx_stall(reg))
-			{
-				int_error_stop(drv_data, "interrupt_transfer: "
-						"rx stall failed");
-				return IRQ_HANDLED;
-			}
-			if (!drv_data->read(drv_data))
-			{
-				int_error_stop(drv_data,
-						"interrupt_transfer: "
-						"trailing byte read failed");
-				return IRQ_HANDLED;
+
+			sccr1_reg &= ~SSCR1_RFT;
+
+			bytes_left = drv_data->rx_end - drv_data->rx;
+			switch (drv_data->n_bytes) {
+			case 4:
+				bytes_left >>= 1;
+			case 2:
+				bytes_left >>= 1;
 			}
-			int_transfer_complete(drv_data);
+
+			if (bytes_left > RX_THRESH_DFLT)
+				bytes_left = RX_THRESH_DFLT;
+
+			sccr1_reg |= SSCR1_RxTresh(bytes_left);
 		}
+		write_SSCR1(sccr1_reg, reg);
 	}
 
 	/* We did something */