mtd, nand, omap2: parse cmdline partition fail

Heiko Schocher
2015-12-04T06:48:45Z

Hello Frans,

I just tried current mainline kernel:
commit 2255702db4014d1c69d6037ed7bdad2d2e271985
Merge: 9e5d25e c86576e
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Mon Nov 30 16:06:44 2015 -0800

Merge tag 'mn10300-for-linus-v4.4-rc4' of
git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

on an am3517 based board (mainlining soon). And with your commit:
commit 853f1c58c4b2: mtd: nand: omap2: show parent device structure in sysfs

MTD partitions from cmdline are not longer detected:

[ 2.087305] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xcc
[ 2.094097] nand: Micron MT29F4G16ABADAWP
[ 2.098303] nand: 512 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
[ 2.106296] nand: WARNING: MT29F4G16ABADAWP: the ECC used on your system is too weak compared to
the one required by the NAND chip
[ 2.118674] MT29F4G16ABADAWP: 'partitions' subnode not found on /ocp/gpmc@6e000000/nand@0,0.
Trying to parse direct subnodes as partitions.
[...]

before this patch it worked:
[ 2.307444] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xcc
[ 2.314092] nand: Micron MT29F4G16ABADAWP
[ 2.318348] nand: 512 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
[ 2.326331] nand: WARNING: omap2-nand.0: the ECC used on your system is too weak compared to the
one required by the NAND chip
[ 2.338336] 5 cmdlinepart partitions found on MTD device omap2-nand.0
[ 2.345129] Creating 5 MTD partitions on "omap2-nand.0":
[ 2.350704] 0x000000000000-0x000000080000 : "MLO"
[ 2.366877] 0x000000080000-0x000000180000 : "u-boot"
[ 2.379179] 0x000000180000-0x0000001c0000 : "env1"
[ 2.390627] 0x0000001c0000-0x000000200000 : "env2"
[ 2.402255] 0x000000200000-0x000020000000 : "common_data"

Reason is taht the mtd->name has changed from "omap2-nand.0" to the
nand chip name ...

If I revert this part from the patch

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 93f664c..28dcf66 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1685,6 +1685,7 @@ static int omap_nand_probe(struct platform_device *pdev)
info->ecc_opt = pdata->ecc_opt;
mtd = &info->mtd;
mtd->priv = &info->nand;
+ mtd->name = dev_name(&pdev->dev);
mtd->dev.parent = &pdev->dev;
nand_chip = &info->nand;
nand_chip->ecc.priv = NULL;

It works again ...

So the question is, is it intended to change the "mtd->name"?
But wondering, if there are two or more identical nand chips in the
system, they will have the same mtd->name ... which seems buggy to me...

bye,
Heiko
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