[PATCH 07/25] mwifiex: don't use [delayed_]work_pending()

From: Tejun Heo
Date: Fri Dec 21 2012 - 20:58:04 EST


Drop work_pending() test from mwifiex_sdio_card_reset(). As
work_pending() becomes %false before sdio_card_reset_worker() starts
executing, it doesn't really protect anything. reset_host may change
between mmc_remove_host() and mmc_add_host(). Make
sdio_card_reset_worker() cache the target mmc_host so that it isn't
affected by mwifiex_sdio_card_reset() racing with it.

Only compile tested.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Bing Zhao <bzhao@xxxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
---
Please let me know how this patch should be routed. I can take it
through the workqueue tree if necessary.

Thanks.

drivers/net/wireless/mwifiex/sdio.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/mwifiex/sdio.c b/drivers/net/wireless/mwifiex/sdio.c
index 5a1c1d0..f2874c3 100644
--- a/drivers/net/wireless/mwifiex/sdio.c
+++ b/drivers/net/wireless/mwifiex/sdio.c
@@ -1752,6 +1752,8 @@ mwifiex_update_mp_end_port(struct mwifiex_adapter *adapter, u16 port)
static struct mmc_host *reset_host;
static void sdio_card_reset_worker(struct work_struct *work)
{
+ struct mmc_host *target = reset_host;
+
/* The actual reset operation must be run outside of driver thread.
* This is because mmc_remove_host() will cause the device to be
* instantly destroyed, and the driver then needs to end its thread,
@@ -1761,10 +1763,10 @@ static void sdio_card_reset_worker(struct work_struct *work)
*/

pr_err("Resetting card...\n");
- mmc_remove_host(reset_host);
+ mmc_remove_host(target);
/* 20ms delay is based on experiment with sdhci controller */
mdelay(20);
- mmc_add_host(reset_host);
+ mmc_add_host(target);
}
static DECLARE_WORK(card_reset_work, sdio_card_reset_worker);

@@ -1773,9 +1775,6 @@ static void mwifiex_sdio_card_reset(struct mwifiex_adapter *adapter)
{
struct sdio_mmc_card *card = adapter->card;

- if (work_pending(&card_reset_work))
- return;
-
reset_host = card->func->card->host;
schedule_work(&card_reset_work);
}
--
1.8.0.2

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