[PATCH v2 02/60] mtd: core: set some defaults when dev.parent is set

From: Frans Klaver
Date: Wed Jun 10 2015 - 16:56:08 EST


If a parent device is set, add_mtd_device() has enough knowledge to fill
in some sane default values for the module name and owner. Do so if they
aren't already set.

Signed-off-by: Frans Klaver <fransklaver@xxxxxxxxx>

---
v1..v2
- Apparently we can get here without a driver set, causing a NULL
dereference[0]. Check that a driver is there before copying the
owner. It does mean that parent devices that don't seem to be
having a driver lying around still can't produce an owner. I suppose
the effect is not much different from it was before.
- Change wording of debug message to mention the fact we're talking
about parent device symlinks here.

[0] https://lkml.org/lkml/2015/4/16/15
---
drivers/mtd/mtdcore.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index d7967cc..0bd1761 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -413,6 +413,15 @@ int add_mtd_device(struct mtd_info *mtd)
mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;

+ if (mtd->dev.parent) {
+ if (!mtd->owner && mtd->dev.parent->driver)
+ mtd->owner = mtd->dev.parent->driver->owner;
+ if (!mtd->name)
+ mtd->name = dev_name(mtd->dev.parent);
+ } else {
+ pr_debug("mtd device won't show a device symlink in sysfs\n");
+ }
+
/* Some chips always power up locked. Unlock them now */
if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
error = mtd_unlock(mtd, 0, mtd->size);
--
2.4.0

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