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authorGeert Uytterhoeven <geert@linux-m68k.org>2013-10-29 13:03:04 +0400
committerLee Jones <lee.jones@linaro.org>2013-11-11 15:22:15 +0400
commit03e361b25ee8dfb1fd9b890072c23c4aae01c6c7 (patch)
tree6adc9cb64eb9c7e7b84cb24880786aa0b9094d5a /drivers/mfd
parent24f76f37aab7cfd97e17976b41182817e887f0e1 (diff)
downloadlinux-03e361b25ee8dfb1fd9b890072c23c4aae01c6c7.tar.xz
mfd: Stop setting refcounting pointers in original mfd_cell arrays
Commit 1e29af62f2b285bd18685da93c3ce8c33ca2d1db ("mfd: Add refcounting support to mfd_cells") had to drop the "const" keyword on the "cell" parameter of mfd_add_devices(), as it added the refcounting pointers to the objects of the passed mfd_cell array itself. However, the mfd core code operates on copies of the mfd_cell objects, so there's no need to modify the originally passed objects. Hence, move the setting of the refcounting pointers from mfd_add_devices() to mfd_platform_add_cell(), where the copy of the mfd_cell objects is made. mfd_clone_cell() can just pass (a copy of) the original usage_count pointer. This allows to make the "cell" parameter of mfd_add_devices() "const" again, and avoids future race conditions when registering multiple instances of the same device in parallel. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'drivers/mfd')
-rw-r--r--drivers/mfd/mfd-core.c17
1 files changed, 9 insertions, 8 deletions
diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index f421586f29fb..8736f4539bc0 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -63,7 +63,8 @@ int mfd_cell_disable(struct platform_device *pdev)
EXPORT_SYMBOL(mfd_cell_disable);
static int mfd_platform_add_cell(struct platform_device *pdev,
- const struct mfd_cell *cell)
+ const struct mfd_cell *cell,
+ atomic_t *usage_count)
{
if (!cell)
return 0;
@@ -72,11 +73,12 @@ static int mfd_platform_add_cell(struct platform_device *pdev,
if (!pdev->mfd_cell)
return -ENOMEM;
+ pdev->mfd_cell->usage_count = usage_count;
return 0;
}
static int mfd_add_device(struct device *parent, int id,
- const struct mfd_cell *cell,
+ const struct mfd_cell *cell, atomic_t *usage_count,
struct resource *mem_base,
int irq_base, struct irq_domain *domain)
{
@@ -115,7 +117,7 @@ static int mfd_add_device(struct device *parent, int id,
goto fail_res;
}
- ret = mfd_platform_add_cell(pdev, cell);
+ ret = mfd_platform_add_cell(pdev, cell, usage_count);
if (ret)
goto fail_res;
@@ -180,7 +182,7 @@ fail_alloc:
}
int mfd_add_devices(struct device *parent, int id,
- struct mfd_cell *cells, int n_devs,
+ const struct mfd_cell *cells, int n_devs,
struct resource *mem_base,
int irq_base, struct irq_domain *domain)
{
@@ -195,8 +197,7 @@ int mfd_add_devices(struct device *parent, int id,
for (i = 0; i < n_devs; i++) {
atomic_set(&cnts[i], 0);
- cells[i].usage_count = &cnts[i];
- ret = mfd_add_device(parent, id, cells + i, mem_base,
+ ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base,
irq_base, domain);
if (ret)
break;
@@ -259,8 +260,8 @@ int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
for (i = 0; i < n_clones; i++) {
cell_entry.name = clones[i];
/* don't give up if a single call fails; just report error */
- if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0,
- NULL))
+ if (mfd_add_device(pdev->dev.parent, -1, &cell_entry,
+ cell_entry.usage_count, NULL, 0, NULL))
dev_err(dev, "failed to create platform device '%s'\n",
clones[i]);
}