From: Lothar Waßmann <LW@KARO-electronics.de>
Date: Mon, 13 Mar 2017 15:09:19 +0000 (+0100)
Subject: drivers: spmi: msm: add timeout to function waiting for SPMI_STATUS_DONE
X-Git-Tag: KARO-TXSD-2017-03-15~10
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=81d7676a0476f887f7072d56af58df2827bbfd5e;p=karo-tx-uboot.git

drivers: spmi: msm: add timeout to function waiting for SPMI_STATUS_DONE

It is always a bad idea(TM) to wait indefinitely for any hardware
related operation to conclude. HW _will_ get faulty some day and don't
react as expected. Thus add a timeout to the loop waiting for
SPMI_STATUS_DONE to be set.
---

diff --git a/drivers/spmi/spmi-msm.c b/drivers/spmi/spmi-msm.c
index a1e6df4445..44062c46d0 100644
--- a/drivers/spmi/spmi-msm.c
+++ b/drivers/spmi/spmi-msm.c
@@ -73,6 +73,7 @@ static int msm_spmi_write(struct udevice *dev, int usid, int pid, int off,
 	struct msm_spmi_priv *priv = dev_get_priv(dev);
 	unsigned channel;
 	uint32_t reg = 0;
+	int timeout = SPMI_WRITE_TIMEOUT;
 
 	if (usid >= SPMI_MAX_SLAVES)
 		return -EINVAL;
@@ -104,10 +105,16 @@ static int msm_spmi_write(struct udevice *dev, int usid, int pid, int off,
 	writel(reg, priv->spmi_chnls + SPMI_CH_OFFSET(channel) + SPMI_REG_CMD0);
 
 	/* Wait till CMD DONE status */
-	reg = 0;
-	while (!reg) {
-		reg = readl(priv->spmi_core + SPMI_CH_OFFSET(channel) +
+	do {
+		reg = readl(priv->spmi_chnls + SPMI_CH_OFFSET(channel) +
 			    SPMI_REG_STATUS);
+		if (reg)
+			break;
+		udelay(1);
+	} while (timeout-- > 0);
+	if (!(reg & SPMI_STATUS_DONE)) {
+		printf("SPMI write timed out\n");
+		return -ETIMEDOUT;
 	}
 
 	if (reg ^ SPMI_STATUS_DONE) {