Fixes for 4.14

Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/queue-4.14/pinctrl-at91-pio4-use-dedicated-lock-class-for-irq.patch b/queue-4.14/pinctrl-at91-pio4-use-dedicated-lock-class-for-irq.patch
new file mode 100644 (file)
index 0000000..2256521
--- /dev/null
+++ b/queue-4.14/pinctrl-at91-pio4-use-dedicated-lock-class-for-irq.patch
@@ -0,0 +1,121 @@
+From 24904eeb4c8c9b2f4b03b5335af926e208a3120e Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Fri, 15 Dec 2023 22:34:24 +0100
+Subject: pinctrl: at91-pio4: use dedicated lock class for IRQ
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Alexis Lothoré <alexis.lothore@bootlin.com>
+
+[ Upstream commit 14694179e561b5f2f7e56a0f590e2cb49a9cc7ab ]
+
+Trying to suspend to RAM on SAMA5D27 EVK leads to the following lockdep
+warning:
+
+ ============================================
+ WARNING: possible recursive locking detected
+ 6.7.0-rc5-wt+ #532 Not tainted
+ --------------------------------------------
+ sh/92 is trying to acquire lock:
+ c3cf306c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100
+
+ but task is already holding lock:
+ c3d7c46c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100
+
+ other info that might help us debug this:
+  Possible unsafe locking scenario:
+
+        CPU0
+        ----
+   lock(&irq_desc_lock_class);
+   lock(&irq_desc_lock_class);
+
+  *** DEADLOCK ***
+
+  May be due to missing lock nesting notation
+
+ 6 locks held by sh/92:
+  #0: c3aa0258 (sb_writers#6){.+.+}-{0:0}, at: ksys_write+0xd8/0x178
+  #1: c4c2df44 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x138/0x284
+  #2: c32684a0 (kn->active){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x148/0x284
+  #3: c232b6d4 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x13c/0x4e8
+  #4: c387b088 (&dev->mutex){....}-{3:3}, at: __device_suspend+0x1e8/0x91c
+  #5: c3d7c46c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100
+
+ stack backtrace:
+ CPU: 0 PID: 92 Comm: sh Not tainted 6.7.0-rc5-wt+ #532
+ Hardware name: Atmel SAMA5
+  unwind_backtrace from show_stack+0x18/0x1c
+  show_stack from dump_stack_lvl+0x34/0x48
+  dump_stack_lvl from __lock_acquire+0x19ec/0x3a0c
+  __lock_acquire from lock_acquire.part.0+0x124/0x2d0
+  lock_acquire.part.0 from _raw_spin_lock_irqsave+0x5c/0x78
+  _raw_spin_lock_irqsave from __irq_get_desc_lock+0xe8/0x100
+  __irq_get_desc_lock from irq_set_irq_wake+0xa8/0x204
+  irq_set_irq_wake from atmel_gpio_irq_set_wake+0x58/0xb4
+  atmel_gpio_irq_set_wake from irq_set_irq_wake+0x100/0x204
+  irq_set_irq_wake from gpio_keys_suspend+0xec/0x2b8
+  gpio_keys_suspend from dpm_run_callback+0xe4/0x248
+  dpm_run_callback from __device_suspend+0x234/0x91c
+  __device_suspend from dpm_suspend+0x224/0x43c
+  dpm_suspend from dpm_suspend_start+0x9c/0xa8
+  dpm_suspend_start from suspend_devices_and_enter+0x1e0/0xa84
+  suspend_devices_and_enter from pm_suspend+0x460/0x4e8
+  pm_suspend from state_store+0x78/0xe4
+  state_store from kernfs_fop_write_iter+0x1a0/0x284
+  kernfs_fop_write_iter from vfs_write+0x38c/0x6f4
+  vfs_write from ksys_write+0xd8/0x178
+  ksys_write from ret_fast_syscall+0x0/0x1c
+ Exception stack(0xc52b3fa8 to 0xc52b3ff0)
+ 3fa0:                   00000004 005a0ae8 00000001 005a0ae8 00000004 00000001
+ 3fc0: 00000004 005a0ae8 00000001 00000004 00000004 b6c616c0 00000020 0059d190
+ 3fe0: 00000004 b6c61678 aec5a041 aebf1a26
+
+This warning is raised because pinctrl-at91-pio4 uses chained IRQ. Whenever
+a wake up source configures an IRQ through irq_set_irq_wake, it will
+lock the corresponding IRQ desc, and then call irq_set_irq_wake on "parent"
+IRQ which will do the same on its own IRQ desc, but since those two locks
+share the same class, lockdep reports this as an issue.
+
+Fix lockdep false positive by setting a different class for parent and
+children IRQ
+
+Fixes: 776180848b57 ("pinctrl: introduce driver for Atmel PIO4 controller")
+Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
+Link: https://lore.kernel.org/r/20231215-lockdep_warning-v1-1-8137b2510ed5@bootlin.com
+Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/pinctrl/pinctrl-at91-pio4.c | 8 ++++++++
+ 1 file changed, 8 insertions(+)
+
+diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
+index 8f18a35b66b61..5ef7dd8c9ccf0 100644
+--- a/drivers/pinctrl/pinctrl-at91-pio4.c
++++ b/drivers/pinctrl/pinctrl-at91-pio4.c
+@@ -899,6 +899,13 @@ static const struct of_device_id atmel_pctrl_of_match[] = {
+       }
+ };
+ 
++/*
++ * This lock class allows to tell lockdep that parent IRQ and children IRQ do
++ * not share the same class so it does not raise false positive
++ */
++static struct lock_class_key atmel_lock_key;
++static struct lock_class_key atmel_request_key;
++
+ static int atmel_pinctrl_probe(struct platform_device *pdev)
+ {
+       struct device *dev = &pdev->dev;
+@@ -1044,6 +1051,7 @@ static int atmel_pinctrl_probe(struct platform_device *pdev)
+               irq_set_chip_and_handler(irq, &atmel_gpio_irq_chip,
+                                        handle_simple_irq);
+               irq_set_chip_data(irq, atmel_pioctrl);
++              irq_set_lockdep_class(irq, &atmel_lock_key, &atmel_request_key);
+               dev_dbg(dev,
+                       "atmel gpio irq domain: hwirq: %d, linux irq: %d\n",
+                       i, irq);
+-- 
+2.43.0
+

diff --git a/queue-4.14/series b/queue-4.14/series
index f0d993c37b77c112ccbde7e1f870b509e0575f90..33d420418e8db7dde9ce50a7aaac0d2b5b3b687c 100644 (file)
--- a/queue-4.14/series
+++ b/queue-4.14/series
@@ -4,3 +4,4 @@ wifi-mac80211-mesh_plink-fix-matches_local-logic.patch
 net-sched-ife-fix-potential-use-after-free.patch
 ethernet-atheros-fix-a-memleak-in-atl1e_setup_ring_r.patch
 net-check-vlan-filter-feature-in-vlan_vids_add_by_de.patch
+pinctrl-at91-pio4-use-dedicated-lock-class-for-irq.patch