lkml.org 
[lkml]   [2011]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 1/1]mmc: fix division by zero when calculate mmc erase time
Since if clock gating feature is enabled, the clock frequency may be zero when
host clock is gated. In such scenario, mmc_set_mmc_erase_timeout() may have a
division by zero bug.

So this patch used mmc_host_clk_rate() to fix this.

Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
---
drivers/mmc/core/core.c | 10 ++++++++--
1 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 34a7e8c..12d0eb8 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1201,8 +1201,14 @@ static void mmc_set_mmc_erase_timeout(struct mmc_card *card,
* less but not that much less, so fudge it by multiplying by 2.
*/
timeout_clks <<= 1;
- timeout_us += (timeout_clks * 1000) /
- (card->host->ios.clock / 1000);
+
+ /*
+ * at this moment, host controller maybe clock gated, so make
+ * sure we can get a correct host clock freq.
+ */
+ if (mmc_host_clk_rate(card->host))
+ timeout_us += (timeout_clks * 1000) /
+ (mmc_host_clk_rate(card->host) / 1000);

erase_timeout = timeout_us / 1000;

--
1.6.6.1


\
 
 \ /
  Last update: 2011-02-24 12:27    [from the cache]
©2003-2011 Jasper Spaans