Messages in this thread | | | Date | Tue, 5 Dec 2017 11:28:15 +0100 | From | Boris Brezillon <> | Subject | Re: [PATCH] mtd: nand: squash struct nand_buffers into struct nand_chip |
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On Tue, 5 Dec 2017 19:02:26 +0900 Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> Hi Boris, > > 2017-12-04 18:10 GMT+09:00 Boris Brezillon > <boris.brezillon@free-electrons.com>: > > >> } > >> > >> if (!(chip->options & NAND_OWN_BUFFERS)) { > >> - nbuf = kzalloc(sizeof(*nbuf), GFP_KERNEL); > >> - if (!nbuf) > >> + chip->ecccalc = kmalloc(mtd->oobsize, GFP_KERNEL); > >> + if (!chip->ecccalc) > >> return -ENOMEM; > >> > >> - nbuf->ecccalc = kmalloc(mtd->oobsize, GFP_KERNEL); > >> - if (!nbuf->ecccalc) { > >> + chip->ecccode = kmalloc(mtd->oobsize, GFP_KERNEL); > >> + if (!chip->ecccode) { > >> ret = -ENOMEM; > >> goto err_free_nbuf; > >> } > > > > Hm, again not directly related to this patch, but I wonder if we > > couldn't allocate those buffers only when they are really needed. > > For example, most NAND controllers do the ECC calculation/correct > > in HW and simply don't need those buffers. > > > The only idea I came up with is to add a new flag, > but I am not sure if you are happy with it > because we are removing NAND_OWN_BUFFERS.
All drivers using ->calc/code_buf are providing a ->correct() and/or ->calculate() method, so I thought we could make the allocation dependent on the presence of one of these hooks [1].
The only exception is the denali driver, but I think we can patch it to not use the ->code_buf buffer [2].
[1]http://code.bulix.org/2ks7yp-236649 [2]http://code.bulix.org/sxqx7o-236650
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