[067/244] mmc: core: use non-reentrant workqueue for clock gating

[Greg KH]

3.0-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>

commit 50a50f9248497484c678631a9c1a719f1aaeab79 upstream.

The default multithread workqueue can cause the same work to be executed
concurrently on a different CPUs. This isn't really suitable for clock
gating as it might already gated the clock and gating it twice results both
host->clk_old and host->ios.clock to be set to 0.

To prevent this from happening we use system_nrt_wq instead.

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Tested-by: Chris Ball <cjb@xxxxxxxxxx>
Signed-off-by: Chris Ball <cjb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/mmc/core/host.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -179,7 +179,7 @@ void mmc_host_clk_release(struct mmc_hos
 	host->clk_requests--;
 	if (mmc_host_may_gate_card(host->card) &&
 	    !host->clk_requests)
-		schedule_work(&host->clk_gate_work);
+		queue_work(system_nrt_wq, &host->clk_gate_work);
 	spin_unlock_irqrestore(&host->clk_lock, flags);
 }
 


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