This fixes the random kernel crash seen while removing the driver, when
running the load/unload test over multiple iterations.
1) modprobe btnxpuart
2) hciconfig hci0 reset
3) hciconfig (check hci0 interface up with valid BD address)
4) modprobe -r btnxpuart
Repeat steps 1 to 4
The ps_wakeup() call in btnxpuart_close() schedules the psdata->work(),
which gets scheduled after module is removed, causing a kernel crash.
This hidden issue got highlighted after enabling Power Save by default
in 4183a7be7700 (Bluetooth: btnxpuart: Enable Power Save feature on
startup)
The new ps_cleanup() deasserts UART break immediately while closing
serdev device, cancels any scheduled ps_work and destroys the ps_lock
mutex.
[ 85.884604] Unable to handle kernel paging request at virtual address ffffd4a61638f258
[ 85.884624] Mem abort info:
[ 85.884625] ESR = 0x0000000086000007
[ 85.884628] EC = 0x21: IABT (current EL), IL = 32 bits
[ 85.884633] SET = 0, FnV = 0
[ 85.884636] EA = 0, S1PTW = 0
[ 85.884638] FSC = 0x07: level 3 translation fault
[ 85.884642] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000041dd0000
[ 85.884646] [ffffd4a61638f258] pgd=1000000095fff003, p4d=1000000095fff003, pud=100000004823d003, pmd=100000004823e003, pte=0000000000000000
[ 85.884662] Internal error: Oops: 0000000086000007 [#1] PREEMPT SMP
[ 85.890932] Modules linked in: algif_hash algif_skcipher af_alg overlay fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine authenc libdes crct10dif_ce polyval_ce polyval_generic snd_soc_imx_spdif snd_soc_imx_card snd_soc_ak5558 snd_soc_ak4458 caam secvio error snd_soc_fsl_spdif snd_soc_fsl_micfil snd_soc_fsl_sai snd_soc_fsl_utils gpio_ir_recv rc_core fuse [last unloaded: btnxpuart(O)]
[ 85.927297] CPU: 1 PID: 67 Comm: kworker/1:3 Tainted: G O 6.1.36+g937b1be4345a #1
[ 85.936176] Hardware name: FSL i.MX8MM EVK board (DT)
[ 85.936182] Workqueue: events 0xffffd4a61638f380
[ 85.936198] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 85.952817] pc : 0xffffd4a61638f258
[ 85.952823] lr : 0xffffd4a61638f258
[ 85.952827] sp : ffff8000084fbd70
[ 85.952829] x29: ffff8000084fbd70 x28: 0000000000000000 x27: 0000000000000000
[ 85.963112] x26: ffffd4a69133f000 x25: ffff4bf1c8540990 x24: ffff4bf215b87305
[ 85.963119] x23: ffff4bf215b87300 x22: ffff4bf1c85409d0 x21: ffff4bf1c8540970
[ 85.977382] x20: 0000000000000000 x19: ffff4bf1c8540880 x18: 0000000000000000
[ 85.977391] x17: 0000000000000000 x16: 0000000000000133 x15: 0000ffffe2217090
[ 85.977399] x14: 0000000000000001 x13: 0000000000000133 x12: 0000000000000139
[ 85.977407] x11: 0000000000000001 x10: 0000000000000a60 x9 : ffff8000084fbc50
[ 85.977417] x8 : ffff4bf215b7d000 x7 : ffff4bf215b83b40 x6 : 00000000000003e8
[ 85.977424] x5 : 00000000410fd030 x4 : 0000000000000000 x3 : 0000000000000000
[ 85.977432] x2 : 0000000000000000 x1 : ffff4bf1c4265880 x0 : 0000000000000000
[ 85.977443] Call trace:
[ 85.977446] 0xffffd4a61638f258
[ 85.977451] 0xffffd4a61638f3e8
[ 85.977455] process_one_work+0x1d4/0x330
[ 85.977464] worker_thread+0x6c/0x430
[ 85.977471] kthread+0x108/0x10c
[ 85.977476] ret_from_fork+0x10/0x20
[ 85.977488] Code: bad PC value
[ 85.977491] ---[ end trace 0000000000000000 ]---
Preset since v6.9.11
Fixes: 86d55f124b52 ("Bluetooth: btnxpuart: Deasset UART break before closing serdev device")
Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@xxxxxxx>
Reviewed-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
---
v2: Add details to commit message (Paul Menzel)
---
drivers/bluetooth/btnxpuart.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
index f75b24bd3045..4bac4a81249c 100644
--- a/drivers/bluetooth/btnxpuart.c
+++ b/drivers/bluetooth/btnxpuart.c
@@ -449,6 +449,23 @@ static bool ps_wakeup(struct btnxpuart_dev *nxpdev)
return false;
}
+static void ps_cleanup(struct btnxpuart_dev *nxpdev)
+{
+ struct ps_data *psdata = &nxpdev->psdata;
+ u8 ps_state;
+
+ mutex_lock(&psdata->ps_lock);
+ ps_state = psdata->ps_state;
+ mutex_unlock(&psdata->ps_lock);
+
+ if (ps_state != PS_STATE_AWAKE)
+ ps_control(psdata->hdev, PS_STATE_AWAKE);
+
+ ps_cancel_timer(nxpdev);
+ cancel_work_sync(&psdata->work);
+ mutex_destroy(&psdata->ps_lock);
+}
+
static int send_ps_cmd(struct hci_dev *hdev, void *data)
{
struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
@@ -1363,7 +1380,6 @@ static int btnxpuart_close(struct hci_dev *hdev)
{
struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
- ps_wakeup(nxpdev);
serdev_device_close(nxpdev->serdev);
skb_queue_purge(&nxpdev->txq);
if (!IS_ERR_OR_NULL(nxpdev->rx_skb)) {
@@ -1516,8 +1532,8 @@ static void nxp_serdev_remove(struct serdev_device *serdev)
nxpdev->new_baudrate = nxpdev->fw_init_baudrate;
nxp_set_baudrate_cmd(hdev, NULL);
}
- ps_cancel_timer(nxpdev);
}
+ ps_cleanup(nxpdev);
hci_unregister_dev(hdev);
hci_free_dev(hdev);
}
--
2.34.1
