[PATCH] MTD: OneNAND: Avoid deadlock in erase callback; release chip lock first.
joern at logfs.org
Fri Oct 12 03:58:05 EDT 2007
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)
> 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 */
> + /* Do call back function */
> + if (!ret)
> + mtd_erase_callback(instr);
> return ret;
But this is not to say that the main benefit of Linux and other GPL
software is lower-cost. Control is the main benefit--cost is secondary.
-- Bruce Perens
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