From: Christophe JAILLET christophe.jaillet@wanadoo.fr
stable inclusion from stable-v5.10.117 commit 9e40f2c513926371b30eebb14e5648378d11ba2e category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L66B
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit ab244be47a8f111bc82496a8a20c907236e37f95 ]
If successful ida_simple_get() calls are not undone when needed, some additional memory may be allocated and wasted.
Here, an ID between 0 and MAX_INT is required. If this ID is >=100, it is not taken into account and is wasted. It should be released.
Instead of calling ida_simple_remove(), take advantage of the 'max' parameter to require the ID not to be too big. Should it be too big, it is not allocated and don't need to be freed.
While at it, use ida_alloc_xxx()/ida_free() instead to ida_simple_get()/ida_simple_remove(). The latter is deprecated and more verbose.
Fixes: db1a0ae21461 ("drm/nouveau/bl: Assign different names to interfaces") Signed-off-by: Christophe JAILLET christophe.jaillet@wanadoo.fr Reviewed-by: Lyude Paul lyude@redhat.com [Fixed formatting warning from checkpatch] Signed-off-by: Lyude Paul lyude@redhat.com Link: https://patchwork.freedesktop.org/patch/msgid/9ba85bca59df6813dc029e743a8364... Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- drivers/gpu/drm/nouveau/nouveau_backlight.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c index c7a94c94dbf3..f2f3280c3a50 100644 --- a/drivers/gpu/drm/nouveau/nouveau_backlight.c +++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c @@ -51,8 +51,9 @@ static bool nouveau_get_backlight_name(char backlight_name[BL_NAME_SIZE], struct nouveau_backlight *bl) { - const int nb = ida_simple_get(&bl_ida, 0, 0, GFP_KERNEL); - if (nb < 0 || nb >= 100) + const int nb = ida_alloc_max(&bl_ida, 99, GFP_KERNEL); + + if (nb < 0) return false; if (nb > 0) snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb); @@ -280,7 +281,7 @@ nouveau_backlight_init(struct drm_connector *connector) nv_encoder, ops, &props); if (IS_ERR(bl->dev)) { if (bl->id >= 0) - ida_simple_remove(&bl_ida, bl->id); + ida_free(&bl_ida, bl->id); ret = PTR_ERR(bl->dev); goto fail_alloc; } @@ -306,7 +307,7 @@ nouveau_backlight_fini(struct drm_connector *connector) return;
if (bl->id >= 0) - ida_simple_remove(&bl_ida, bl->id); + ida_free(&bl_ida, bl->id);
backlight_device_unregister(bl->dev); nv_conn->backlight = NULL;