Messages in this thread | | | Date | Mon, 1 Nov 2021 08:38:24 +0100 | From | Boris Brezillon <> | Subject | Re: [PATCH v4 1/4] mtd: rawnand: nand_bbt: hide suspend/resume hooks while scanning bbt |
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On Tue, 26 Oct 2021 07:55:48 +0200 Sean Nyekjaer <sean@geanix.com> wrote:
> From: Boris Brezillon <boris.brezillon@collabora.com> > > The BBT scan logic use the MTD helpers before the MTD layer had a > chance to initialize the device, and that leads to issues when > accessing the uninitialized suspend lock. Let's temporarily set the > suspend/resume hooks to NULL to skip the lock acquire/release step. > > Fixes: 013e6292aaf5 ("mtd: rawnand: Simplify the locking")
I think I already mentioned this Fixes tag should not be there.
> Tested-by: Sean Nyekjaer <sean@geanix.com> > Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> > Signed-off-by: Sean Nyekjaer <sean@geanix.com> > --- > drivers/mtd/nand/raw/nand_bbt.c | 28 +++++++++++++++++++++++++++- > 1 file changed, 27 insertions(+), 1 deletion(-) > > diff --git a/drivers/mtd/nand/raw/nand_bbt.c b/drivers/mtd/nand/raw/nand_bbt.c > index b7ad030225f8..93d385703469 100644 > --- a/drivers/mtd/nand/raw/nand_bbt.c > +++ b/drivers/mtd/nand/raw/nand_bbt.c > @@ -1397,8 +1397,28 @@ static int nand_create_badblock_pattern(struct nand_chip *this) > */ > int nand_create_bbt(struct nand_chip *this) > { > + struct mtd_info *mtd = nand_to_mtd(this); > + int (*suspend) (struct mtd_info *) = mtd->_suspend; > + void (*resume) (struct mtd_info *) = mtd->_resume; > int ret; > > + /* > + * The BBT scan logic use the MTD helpers before the MTD layer had a > + * chance to initialize the device, and that leads to issues when > + * accessing the uninitialized suspend lock. Let's temporarily set the > + * suspend/resume hooks to NULL to skip the lock acquire/release step. > + * > + * FIXME: This is an ugly hack, so please don't copy this pattern to > + * other MTD implementations. The proper fix would be to implement a > + * generic BBT scan logic at the NAND level that's not using any of the > + * MTD helpers to access pages. We also might consider doing a two > + * step initialization at the MTD level (mtd_device_init() + > + * mtd_device_register()) so some of the fields are initialized > + * early. > + */ > + mtd->_suspend = NULL; > + mtd->_resume = NULL; > + > /* Is a flash based bad block table requested? */ > if (this->bbt_options & NAND_BBT_USE_FLASH) { > /* Use the default pattern descriptors */ > @@ -1422,7 +1442,13 @@ int nand_create_bbt(struct nand_chip *this) > return ret; > } > > - return nand_scan_bbt(this, this->badblock_pattern); > + ret = nand_scan_bbt(this, this->badblock_pattern); > + > + /* Restore the suspend/resume hooks. */ > + mtd->_suspend = suspend; > + mtd->_resume = resume; > + > + return ret; > } > EXPORT_SYMBOL(nand_create_bbt); >
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