From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from up.free-electrons.com ([163.172.77.33] helo=mail.free-electrons.com) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1c3RdS-0003Eg-E1 for linux-mtd@lists.infradead.org; Sun, 06 Nov 2016 17:53:39 +0000 Date: Sun, 6 Nov 2016 18:53:17 +0100 From: Boris Brezillon To: Zach Brown Cc: , , , , , Subject: Re: [PATCH v3 3/5] mtd: nand: Add bb_per_lun and blocks_per_lun fields to nand_chip Message-ID: <20161106185317.3504896c@bbrezillon> In-Reply-To: <20161101183231.GA13831@zach-desktop> References: <1477686464-7437-1-git-send-email-zach.brown@ni.com> <1477686464-7437-4-git-send-email-zach.brown@ni.com> <20161101145058.65317535@bbrezillon> <20161101183231.GA13831@zach-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 1 Nov 2016 13:32:32 -0500 Zach Brown wrote: > On Tue, Nov 01, 2016 at 02:50:58PM +0100, Boris Brezillon wrote: > > On Fri, 28 Oct 2016 15:27:42 -0500 > > Zach Brown wrote: > > > > > The fields bb_per_lun and blocks_per_lun are useful determining the > > > number of bad blocks a MTD needs to allocate. How they are set will > > > depend on if the chip is ONFI, JEDEC or a fuill-id entry in the nand_ids > > > table. > > > > > > Signed-off-by: Zach Brown > > > --- > > > include/linux/mtd/nand.h | 5 +++++ > > > 1 file changed, 5 insertions(+) > > > > > > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h > > > index c5d3d502..efbe439 100644 > > > --- a/include/linux/mtd/nand.h > > > +++ b/include/linux/mtd/nand.h > > > @@ -771,6 +771,9 @@ nand_get_sdr_timings(const struct nand_data_interface *conf) > > > * supported, 0 otherwise. > > > * @jedec_params: [INTERN] holds the JEDEC parameter page when JEDEC is > > > * supported, 0 otherwise. > > > + * @bb_per_lun: [INTERN] the max number of bad blocks each LUN of a > > > + * this nand device will encounter their life times. > > > + * @blocks_per_lun: [INTERN] The number of PEBs in a LUN > > > * @read_retries: [INTERN] the number of read retry modes supported > > > * @onfi_set_features: [REPLACEABLE] set the features for ONFI nand > > > * @onfi_get_features: [REPLACEABLE] get the features for ONFI nand > > > @@ -853,6 +856,8 @@ struct nand_chip { > > > struct nand_onfi_params onfi_params; > > > struct nand_jedec_params jedec_params; > > > }; > > > + __le16 bb_per_lun; > > > + __le32 blocks_per_lun; > > > > Two things I don't like here: > > - you use little-endian types, while it should use native endianness. > > Make it easier, and just declare those fields as int (or unsigned > > int). > > - you stick to the ONFI spec, while I'd prefer to see the term lun > > replaced by die, and I wonder if we don't already have a field > > storing the number of blocks per die (I might be wrong though). > > > > I looked for an existing field for number of blocks per die and could not find > it. Perhaps you were remembering chipsize? or numchips? I looked at how they > were calculated and chipsize is a multiple of (blocks_per_lun * lun_count) so > it can't be used to find blocks_per_lun without storing lun_count anyways. > Let me know if you think I missed something. Probably not, we so many fields in the nand_chip and mtd_info struct that I don't remember which ones we are missing ;-).