[PATCH v1] mailbox: imx: fix crash in resume on i.mx8ulp

[Robin Gong]

check 'priv->clk' before 'imx_mu_read()' otherwise below crash may happen on
i.mx8ulp, since clock maybe already disabled by runtime suspend.

[   79.155733] Internal error: synchronous external abort: 96000210 [#1] PREEMPT SMP
[   79.162979] Modules linked in:
[   79.165998] CPU: 0 PID: 460 Comm: sh Not tainted 5.10.35-00234-g0b4d749783dc-dirty #571
[   79.173738] Hardware name: NXP i.MX8ULP EVK (DT)
[   79.178240] pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--)
[   79.184082] pc : imx_mu_resume_noirq+0x14/0x78
[   79.188422] lr : dpm_run_callback.isra.0+0x38/0xd8
[   79.193085] sp : ffff80001b63baa0
[   79.196337] x29: ffff80001b63baa0 x28: 0000000000000000
[   79.201512] x27: ffff800011bd9b30 x26: ffff80001157acd0
[   79.206682] x25: ffff800011a210f4 x24: 00000012682e38d8
[   79.211855] x23: 0000000000000000 x22: ffff800011b85000
[   79.217023] x21: ffff00000425c810 x20: 0000000000000010
[   79.222195] x19: ffff800010c79550 x18: 0000000000000010
[   79.227368] x17: 0000000000000000 x16: 0000000000000000
[   79.232539] x15: 0000006fb5d33a2c x14: 000000000000027a
[   79.237709] x13: 0000000000000303 x12: 0000000000000001
[   79.242879] x11: 0000000000000040 x10: ffff000004424f80
[   79.248050] x9 : ffff000004424f78 x8 : 0000000000000028
[   79.253222] x7 : 0000000000000006 x6 : 0000000000000657
[   79.258395] x5 : 0000000000000657 x4 : 0000000000000000
[   79.263567] x3 : 0000000000000001 x2 : 0000000000000110
[   79.268742] x1 : ffff0000054b8080 x0 : ffff80001af40110
[   79.273915] Call trace:
[   79.276340]  imx_mu_resume_noirq+0x14/0x78
[   79.280345]  device_resume_noirq+0x80/0x170
[   79.284431]  dpm_resume_noirq+0xb0/0x218
[   79.288271]  suspend_devices_and_enter+0x20c/0x5b8
[   79.292938]  pm_suspend+0x2ec/0x350
[   79.296362]  state_store+0x88/0x108
[   79.299786]  kobj_attr_store+0x14/0x28
[   79.303460]  sysfs_kf_write+0x40/0x50
[   79.307046]  kernfs_fop_write_iter+0x110/0x1a0
[   79.311388]  new_sync_write+0xe4/0x178
[   79.315062]  vfs_write+0x24c/0x380
[   79.318404]  ksys_write+0x68/0xf0
[   79.321664]  __arm64_sys_write+0x18/0x20
[   79.325508]  el0_svc_common.constprop.0+0x68/0x160
[   79.330179]  do_el0_svc+0x20/0x80
[   79.333436]  el0_svc+0x10/0x18
[   79.336444]  el0_sync_handler+0xa8/0xb0
[   79.340200]  el0_sync+0x140/0x180
[   79.343463] Code: f94a9022 f9400420 b9403c42 8b020000 (b9400000)
[   79.349383] ---[ end trace 4af1de2c96411434 ]---

Signed-off-by: Robin Gong <yibin.gong at nxp.com>
---
 drivers/mailbox/imx-mailbox.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
index 2543c7b6..848c0fe 100644
--- a/drivers/mailbox/imx-mailbox.c
+++ b/drivers/mailbox/imx-mailbox.c
@@ -620,7 +620,7 @@ static int __maybe_unused imx_mu_resume_noirq(struct device *dev)
 	 * send failed, may lead to system freeze. This issue
 	 * is observed by testing freeze mode suspend.
 	 */
-	if (!imx_mu_read(priv, priv->dcfg->xCR) && !priv->clk)
+	if (!priv->clk && !imx_mu_read(priv, priv->dcfg->xCR))
 		imx_mu_write(priv, priv->xcr, priv->dcfg->xCR);
 
 	return 0;
-- 
2.7.4