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pmdomains: mtk-pm-domains: Fix spinlock recursion in probe

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For some reason, of_find_node_with_property() is creating a spinlock
recursion issue along with fwnode_count_parents(), and this issue
is making all MediaTek boards unbootable.

As of kernel v6.18-rc6, there are only three users of this function,
one of which is this driver.

Migrate away from of_find_node_with_property() by adding a local
scpsys_get_legacy_regmap_node() function, which acts similarly to
of_find_node_with_property(), and calling the former in place of
the latter.

This resolves the following spinlock recursion issue:

[    1.773979] BUG: spinlock recursion on CPU#2, kworker/u24:1/60
[    1.790485]  lock: devtree_lock+0x0/0x40, .magic: dead4ead, .owner: kworker/u24:1/60, .owner_cpu: 2
[    1.791644] CPU: 2 UID: 0 PID: 60 Comm: kworker/u24:1 Tainted: G        W           6.18.0-rc6 #3 PREEMPT
[    1.791649] Tainted: [W]=WARN
[    1.791650] Hardware name: MediaTek Genio-510 EVK (DT)
[    1.791653] Workqueue: events_unbound deferred_probe_work_func
[    1.791658] Call trace:
[    1.791659]  show_stack+0x18/0x30 (C)
[    1.791664]  dump_stack_lvl+0x68/0x94
[    1.791668]  dump_stack+0x18/0x24
[    1.791672]  spin_dump+0x78/0x88
[    1.791678]  do_raw_spin_lock+0x110/0x140
[    1.791684]  _raw_spin_lock_irqsave+0x58/0x6c
[    1.791690]  of_get_parent+0x28/0x74
[    1.791694]  of_fwnode_get_parent+0x38/0x7c
[    1.791700]  fwnode_count_parents+0x34/0xf0
[    1.791705]  fwnode_full_name_string+0x28/0x120
[    1.791710]  device_node_string+0x3e4/0x50c
[    1.791715]  pointer+0x294/0x430
[    1.791718]  vsnprintf+0x21c/0x5bc
[    1.791722]  vprintk_store+0x108/0x47c
[    1.791728]  vprintk_emit+0xc4/0x350
[    1.791732]  vprintk_default+0x34/0x40
[    1.791736]  vprintk+0x24/0x30
[    1.791740]  _printk+0x60/0x8c
[    1.791744]  of_node_release+0x154/0x194
[    1.791749]  kobject_put+0xa0/0x120
[    1.791753]  of_node_put+0x18/0x28
[    1.791756]  of_find_node_with_property+0x74/0x100
[    1.791761]  scpsys_probe+0x338/0x5e0
[    1.791765]  platform_probe+0x5c/0xa4
[    1.791770]  really_probe+0xbc/0x2ac
[    1.791774]  __driver_probe_device+0x78/0x118
[    1.791779]  driver_probe_device+0x3c/0x170
[    1.791783]  __device_attach_driver+0xb8/0x150
[    1.791788]  bus_for_each_drv+0x88/0xe8
[    1.791792]  __device_attach+0x9c/0x1a0
[    1.791796]  device_initial_probe+0x14/0x20
[    1.791801]  bus_probe_device+0xa0/0xa4
[    1.791805]  deferred_probe_work_func+0x88/0xd0
[    1.791809]  process_one_work+0x1e8/0x448
[    1.791813]  worker_thread+0x1ac/0x340
[    1.791816]  kthread+0x138/0x220
[    1.791821]  ret_from_fork+0x10/0x20

Fixes: c29345fa5f ("pmdomain: mediatek: Refactor bus protection regmaps retrieval")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>
Tested-by: Macpaul Lin <macpaul.lin@mediatek.com>
Reviewed-by: Macpaul Lin <macpaul.lin@mediatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
AngeloGioacchino Del Regno
2025-11-21 13:52:12 +01:00
committed by Ulf Hansson
parent 6a23ae0a96
commit c1bac49fe9
1 changed files with 15 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/pmdomain/mediatek/mtk-pm-domains.c
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@@ -748,6 +748,18 @@ static void scpsys_domain_cleanup(struct scpsys *scpsys)
}
}
static struct device_node *scpsys_get_legacy_regmap(struct device_node *np, const char *pn)
{
struct device_node *local_node;
for_each_child_of_node(np, local_node) {
if (of_property_present(local_node, pn))
return local_node;
}
return NULL;
}
static int scpsys_get_bus_protection_legacy(struct device *dev, struct scpsys *scpsys)
{
const u8 bp_blocks[3] = {
@@ -769,7 +781,7 @@ static int scpsys_get_bus_protection_legacy(struct device *dev, struct scpsys *s
* this makes it then possible to allocate the array of bus_prot
* regmaps and convert all to the new style handling.
*/
node = of_find_node_with_property(np, "mediatek,infracfg");
node = scpsys_get_legacy_regmap(np, "mediatek,infracfg");
if (node) {
regmap[0] = syscon_regmap_lookup_by_phandle(node, "mediatek,infracfg");
of_node_put(node);
@@ -782,7 +794,7 @@ static int scpsys_get_bus_protection_legacy(struct device *dev, struct scpsys *s
regmap[0] = NULL;
}
node = of_find_node_with_property(np, "mediatek,smi");
node = scpsys_get_legacy_regmap(np, "mediatek,smi");
if (node) {
smi_np = of_parse_phandle(node, "mediatek,smi", 0);
of_node_put(node);
@@ -800,7 +812,7 @@ static int scpsys_get_bus_protection_legacy(struct device *dev, struct scpsys *s
regmap[1] = NULL;
}
node = of_find_node_with_property(np, "mediatek,infracfg-nao");
node = scpsys_get_legacy_regmap(np, "mediatek,infracfg-nao");
if (node) {
regmap[2] = syscon_regmap_lookup_by_phandle(node, "mediatek,infracfg-nao");
num_regmaps++;