[PATCH] MTD: OneNAND: Avoid deadlock in erase callback; release chip lock first.

[Adrian Hunter]

ext Jörn Engel wrote:
> On Fri, 12 October 2007 10:34:01 +0300, Adrian Hunter wrote:
>> When the erase callback performs some other action on the flash, it's
>> highly likely to deadlock unless we actually release the chip lock
>> before calling it.
>>
>> This patch mirrors that same change already done for NAND.
>>
>> Signed-off-by: Adrian Hunter <ext-adrian.hunter at nokia.com>
>> ---
>>  drivers/mtd/onenand/onenand_base.c |    7 ++++---
>>  1 files changed, 4 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
>> index a8c426b..dd28355 100644
>> --- a/drivers/mtd/onenand/onenand_base.c
>> +++ b/drivers/mtd/onenand/onenand_base.c
>> @@ -1711,13 +1711,14 @@ static int onenand_erase(struct mtd_info *mtd, struct erase_info *instr)
>>  erase_exit:
>>  
>>  	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
> 
> Can you move this line down as well?  There is no point in holding the
> lock here and shrinking critical sections - even if only minimally -
> is generally advantageous.
> 
>> -	/* Do call back function */
>> -	if (!ret)
>> -		mtd_erase_callback(instr);
>>  
>>  	/* Deselect and wake up anyone waiting on the device */
>>  	onenand_release_device(mtd);
>>  
>> +	/* Do call back function */
>> +	if (!ret)
>> +		mtd_erase_callback(instr);
>> +
>>  	return ret;
>>  }
> 
> Jörn
> 

I wanted the patch to be the same as NAND

see http://git.infradead.org/?p=mtd-2.6.git;a=commitdiff;h=49defc015ff58fda46a3afa3462dfdfa69bc8401

Anyone who feels strongly should change both places ;-)