[PATCH 1/2] fix-glamo-mci-possible-timeout-overflow.patch

[Andy Green]

The MMC stack hands us a timeout calibrated in SD_CLK clocks, but the
Glamo can only deal with up to 65520 clocks of timeout.  If the stack
handed us a request bigger than this, it would just wrap and the
timeout we actually used would be way too short.

With this patch if that happens, we use the longest timeout we can,
65520 clocks and give it our best shot.

Signed-off-by: Andy Green <andy at openmoko.com>
---

 drivers/mfd/glamo/glamo-mci.c |   19 ++++++++++---------
 1 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/mfd/glamo/glamo-mci.c b/drivers/mfd/glamo/glamo-mci.c
index 7593425..ae3e92d 100644
--- a/drivers/mfd/glamo/glamo-mci.c
+++ b/drivers/mfd/glamo/glamo-mci.c
@@ -338,6 +338,7 @@ static int glamo_mci_send_command(struct glamo_mci_host *host,
 {
 	u8 u8a[6];
 	u16 fire = 0;
+	u16 timeout = 0xfff; /* max glamo MMC timeout, in units of 16 clocks */
 
 	/* if we can't do it, reject as busy */
 	if (!readw_dly(host->base + GLAMO_REG_MMC_RB_STAT1) &
@@ -447,15 +448,15 @@ static int glamo_mci_send_command(struct glamo_mci_host *host,
 		fire |= GLAMO_FIRE_MMC_CC_BASIC; /* "basic command" */
 		break;
 	}
-	/* enforce timeout */
-	if (cmd->data) {
-		if (cmd->data->timeout_clks)
-			writew_dly(cmd->data->timeout_clks >> 4, /* / 16 clks */
-					host->base + GLAMO_REG_MMC_TIMEOUT);
-		else
-			writew_dly(0xfff, host->base + GLAMO_REG_MMC_TIMEOUT);
-	} else
-		writew(0xfff, host->base + GLAMO_REG_MMC_TIMEOUT);
+	/* enforce timeout, clipping at default 65520 clocks if larger */
+	if (cmd->data)
+		/* so long as there is one... */
+		if (cmd->data->timeout_clks &&
+		    /* ... and it is not longer than we can handle */
+		    (cmd->data->timeout_clks <= 0xffff))
+			timeout = cmd->data->timeout_clks >> 4; /* / 16 clks */
+
+	writew(timeout, host->base + GLAMO_REG_MMC_TIMEOUT);
 
 	/* Generate interrupt on txfer */
 	writew_dly((readw_dly(host->base + GLAMO_REG_MMC_BASIC) & 0x3e) |