From: Marek Vasut <marex@denx.de>
Date: Wed, 22 Oct 2014 19:56:01 +0000 (+0200)
Subject: spi: altera: Zap endless loop
X-Git-Tag: v2015.01-rc1~68^2~5
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=80d73338080c83e17fbf3f844052ec71d03ecd13;p=u-boot

spi: altera: Zap endless loop

The driver contained an endless loop when waiting for TX completion,
this is a bad idea since if the hardware fails, the loop might spin
forever. Add timeout and handle it.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Pavel Machek <pavel@denx.de>
Cc: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
Acked-by: Pavel Machek <pavel@denx.de>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
---

diff --git a/drivers/spi/altera_spi.c b/drivers/spi/altera_spi.c
index 373ce30a03..8e898b99c0 100644
--- a/drivers/spi/altera_spi.c
+++ b/drivers/spi/altera_spi.c
@@ -129,6 +129,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 	uint bytes = bitlen / 8;
 	const uchar *txp = dout;
 	uchar *rxp = din;
+	uint32_t reg, start;
 
 	debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
 	      slave->bus, slave->cs, bitlen, bytes, flags);
@@ -154,8 +155,16 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 		debug("%s: tx:%x ", __func__, d);
 		writel(d, &altspi->regs->txdata);
 
-		while (!(readl(&altspi->regs->status) & ALTERA_SPI_STATUS_RRDY_MSK))
-			;
+		start = get_timer(0);
+		while (1) {
+			reg = readl(&altspi->regs->status);
+			if (reg & ALTERA_SPI_STATUS_RRDY_MSK)
+				break;
+			if (get_timer(start) > (CONFIG_SYS_HZ / 1000)) {
+				printf("%s: Transmission timed out!\n", __func__);
+				goto done;
+			}
+		}
 
 		d = readl(&altspi->regs->rxdata);
 		if (rxp)