[PATCH] mtd: Create partname and partid debug files for child MTDs

[PATCH] mtd: Create partname and partid debug files for child MTDs

[Petr Malat]

Partname and partid are set by the upper driver (spi-nor) on the master
MTD. If this MTD is partitioned and CONFIG_MTD_PARTITIONED_MASTER is
disabled, the master MTD is not instantiated and partname and partid
aren't available to the userspace.

Always read the partname and partid from the master MTD, they describe
the HW, which can't differ between master and its children.

Signed-off-by: Petr Malat <oss@malat.biz>
---
 drivers/mtd/mtdcore.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 2d6423d89a17..66fa7f702174 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -361,6 +361,7 @@ static struct dentry *dfs_dir_mtd;
 
 static void mtd_debugfs_populate(struct mtd_info *mtd)
 {
+	struct mtd_info *master = mtd_get_master(mtd);
 	struct device *dev = &mtd->dev;
 	struct dentry *root;
 
@@ -370,12 +371,12 @@ static void mtd_debugfs_populate(struct mtd_info *mtd)
 	root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
 	mtd->dbg.dfs_dir = root;
 
-	if (mtd->dbg.partid)
-		debugfs_create_file("partid", 0400, root, mtd,
+	if (master->dbg.partid)
+		debugfs_create_file("partid", 0400, root, master,
 				    &mtd_partid_debug_fops);
 
-	if (mtd->dbg.partname)
-		debugfs_create_file("partname", 0400, root, mtd,
+	if (master->dbg.partname)
+		debugfs_create_file("partname", 0400, root, master,
 				    &mtd_partname_debug_fops);
 }
 
-- 
2.20.1


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

Re: [PATCH] mtd: Create partname and partid debug files for child MTDs

[Michael Walle]

Hi Petr,

Am 2021-04-30 08:50, schrieb Petr Malat:
> Partname and partid are set by the upper driver (spi-nor) on the master
> MTD. If this MTD is partitioned and CONFIG_MTD_PARTITIONED_MASTER is
> disabled, the master MTD is not instantiated and partname and partid
> aren't available to the userspace.

You might have a look at:
https://lore.kernel.org/linux-mtd/20210429155713.28808-1-michael@walle.cc/

This is just for spi-nor though, but attaches the properties to the
flash device instead of the mtd device.

-michael

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

Re: [PATCH] mtd: Create partname and partid debug files for child MTDs

[Petr Malat]

Hi!
On Fri, Apr 30, 2021 at 09:02:14AM +0200, Michael Walle wrote:
> > Partname and partid are set by the upper driver (spi-nor) on the master
> > MTD. If this MTD is partitioned and CONFIG_MTD_PARTITIONED_MASTER is
> > disabled, the master MTD is not instantiated and partname and partid
> > aren't available to the userspace.
> 
> You might have a look at:
> https://lore.kernel.org/linux-mtd/20210429155713.28808-1-michael@walle.cc/
Thanks, I used it to replace my hack to dump SFDP with print_hex_dump.
As it seems I'm not the only one interested in SFDP in userspace I
have pushed my SFDP parser to github https://github.com/petris/sfdp-parser

> This is just for spi-nor though, but attaches the properties to the
> flash device instead of the mtd device.
Currently, no other driver is using it. If your change makes it in,
debugfs attributes can be removed (or extended to cover other drivers
as well).
  Petr

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

Re: [PATCH] mtd: Create partname and partid debug files for child MTDs

[Miquel Raynal]

On Fri, 2021-04-30 at 06:50:57 UTC, Petr Malat wrote:
> Partname and partid are set by the upper driver (spi-nor) on the master
> MTD. If this MTD is partitioned and CONFIG_MTD_PARTITIONED_MASTER is
> disabled, the master MTD is not instantiated and partname and partid
> aren't available to the userspace.
> 
> Always read the partname and partid from the master MTD, they describe
> the HW, which can't differ between master and its children.
> 
> Signed-off-by: Petr Malat <oss@malat.biz>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git mtd/next, thanks.

Miquel

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/