[PATCH] mmc: mmci: Do not release spinlock in request_end
Ulf Hansson
ulf.hansson at stericsson.com
Fri Oct 14 03:37:51 EDT 2011
Jon Medhurst (Tixy) wrote:
> On Thu, 2011-10-13 at 15:29 +0100, Russell King - ARM Linux wrote:
>> On Tue, Oct 11, 2011 at 04:06:41PM +0200, Ulf Hansson wrote:
>>> The patch "mmc: core: move ->request() call from atomic context",
>>> is the reason to why this change is possible. This simplifies the
>>> error handling code execution path quite a lot and potentially also
>>> fixes some error handling hang problems.
>>>
>>> Signed-off-by: Ulf Hansson <ulf.hansson at stericsson.com>
>> This doesn't look right:
>>
>> void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
>> {
>> if (err && cmd->retries) {
>> host->ops->request(host, mrq);
>>
This is NOT how it looks at mmc-next. You need to test with Adrian
Hunters patch which the commit refers two.
Linux next for mmc is available at:
git://dev.laptop.org/users/cjb/mmc mmc-next
>> So, not dropping the spinlock results in calling the request function
>> with the spinlock held - and as the request function then goes on to
>> lock the spinlock, we will deadlock.
>
> Indeed, deadlock behaviour at this point is what I see with this patch
> on a Versatile Express board running 3.0-rc9.
>
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