2010/12/21 Chris Ball <cjb@xxxxxxxxxx>:
> Hi Linus,
>
> On Wed, Nov 03, 2010 at 10:22:50AM +0100, Linus Walleij wrote:
>> +/*
>> + * mmc_host_clk_exit - shut down clock gating code
>> + * @host: host with potential clock to control
>> + */
>> +static inline void mmc_host_clk_exit(struct mmc_host *host)
>> +{
>> + /*
>> + * Wait for any outstanding gate and then make sure we're
>> + * ungated before exiting.
>> + */
>> + if (cancel_work_sync(&host->clk_disable_work))
>> + mmc_host_clk_gate_delayed(host);
>> + if (host->clk_gated)
>> + mmc_host_clk_ungate(host);
>> + BUG_ON(host->clk_requests > 0);
>> +}
>
> I just hit the BUG_ON() above, when doing "rmmod sdhci-pci" on my x86
> laptop running today's linux-next. There was *no* SD card inserted,
> and hadn't been one inserted all boot.
Hm, it's a plain bug...
We make sure it's ungated the line above so clk_requests is always
== 1.
It should be BUG_ON(host->clk_requests > 1)
Can you try the below:
From: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
Date: Wed, 22 Dec 2010 09:10:04 +0100
Subject: [PATCH] mmc: check for > 1 clk_requests
Since we make sure the clock is enabled in the mmc_host_clk_exit()
function we should expect a reference counter of 1, not 0.
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
---
drivers/mmc/core/host.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 92e3370..072d29c 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -235,7 +235,7 @@ static inline void mmc_host_clk_exit(struct mmc_host *host)
mmc_host_clk_gate_delayed(host);
if (host->clk_gated)
mmc_host_clk_ungate(host);
- BUG_ON(host->clk_requests > 0);
+ BUG_ON(host->clk_requests > 1);
}
#else
--
1.7.3.3
Yours,
Linus Walleij
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