mtd: spear_smi: handle return value of timeouts properly

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=2c99b8bfb22342ab0c06e07ee54fa0d5e638e52a
Commit:     2c99b8bfb22342ab0c06e07ee54fa0d5e638e52a
Parent:     4dc48c37d1ce968b5ade7d1646927199ee536129
Author:     Vipin Kumar <vipin.kumar at st.com>
AuthorDate: Mon Jul 2 11:28:47 2012 +0530
Committer:  David Woodhouse <David.Woodhouse at intel.com>
CommitDate: Fri Jul 6 18:27:48 2012 +0100

    mtd: spear_smi: handle return value of timeouts properly
    
    Handle timouts in general and return value of
    'wait_event_interruptible_timeout' in particular, to capture all
    conditions.
    
    'wait_event_interruptible_timeout' returns either of the following three
    values :-
       * 0               - time out occurred.
       * negative
          * -ERESTARTSYS - return because of a signal
          * other        - for a real error
       * positive        - time remaining
    
    Fix particularly 'ERESTARTSYS' condition which is not properly handled
    by the smi driver at a couple of places leading to an erroneous
    situation.
    
    Signed-off-by: Antonio BORNEO <antonio.borneo at st.com>
    Signed-off-by: Shiraz Hashim <shiraz.hashim at st.com>
    Signed-off-by: Vipin Kumar <vipin.kumar at st.com>
    Signed-off-by: Artem Bityutskiy <artem.bityutskiy at linux.intel.com>
    Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
---
 drivers/mtd/devices/spear_smi.c |   23 +++++++++++++----------
 1 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/mtd/devices/spear_smi.c b/drivers/mtd/devices/spear_smi.c
index aec941e..b85f183 100644
--- a/drivers/mtd/devices/spear_smi.c
+++ b/drivers/mtd/devices/spear_smi.c
@@ -241,8 +241,8 @@ static int spear_smi_read_sr(struct spear_smi *dev, u32 bank)
 	/* copy dev->status (lower 16 bits) in order to release lock */
 	if (ret > 0)
 		ret = dev->status & 0xffff;
-	else
-		ret = -EIO;
+	else if (ret == 0)
+		ret = -ETIMEDOUT;
 
 	/* restore the ctrl regs state */
 	writel(ctrlreg1, dev->io_base + SMI_CR1);
@@ -270,16 +270,19 @@ static int spear_smi_wait_till_ready(struct spear_smi *dev, u32 bank,
 	finish = jiffies + timeout;
 	do {
 		status = spear_smi_read_sr(dev, bank);
-		if (status < 0)
-			continue; /* try till timeout */
-		else if (!(status & SR_WIP))
+		if (status < 0) {
+			if (status == -ETIMEDOUT)
+				continue; /* try till finish */
+			return status;
+		} else if (!(status & SR_WIP)) {
 			return 0;
+		}
 
 		cond_resched();
 	} while (!time_after_eq(jiffies, finish));
 
 	dev_err(&dev->pdev->dev, "smi controller is busy, timeout\n");
-	return status;
+	return -EBUSY;
 }
 
 /**
@@ -395,11 +398,11 @@ static int spear_smi_write_enable(struct spear_smi *dev, u32 bank)
 	writel(ctrlreg1, dev->io_base + SMI_CR1);
 	writel(0, dev->io_base + SMI_CR2);
 
-	if (ret <= 0) {
+	if (ret == 0) {
 		ret = -EIO;
 		dev_err(&dev->pdev->dev,
 			"smi controller failed on write enable\n");
-	} else {
+	} else if (ret > 0) {
 		/* check whether write mode status is set for required bank */
 		if (dev->status & (1 << (bank + WM_SHIFT)))
 			ret = 0;
@@ -466,10 +469,10 @@ static int spear_smi_erase_sector(struct spear_smi *dev,
 	ret = wait_event_interruptible_timeout(dev->cmd_complete,
 			dev->status & TFF, SMI_CMD_TIMEOUT);
 
-	if (ret <= 0) {
+	if (ret == 0) {
 		ret = -EIO;
 		dev_err(&dev->pdev->dev, "sector erase failed\n");
-	} else
+	} else if (ret > 0)
 		ret = 0; /* success */
 
 	/* restore ctrl regs */