Re: [PATCH v1 1/2] Bluetooth: btnxpuart: Fix btnxpuart_close

[Francesco Dolcini]

Hello all,

On Wed, Oct 18, 2023 at 04:55:39PM +0200, Marcel Ziswiler wrote:
> From: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
> 
> Unfortunately, btnxpuart_close() may trigger a BUG: scheduling while
> atomic. Fix this by properly purging the transmit queue and freeing the
> receive skb.
> 
> Fixes: 689ca16e5232 ("Bluetooth: NXP: Add protocol support for NXP Bluetooth chipsets")
> 
> Signed-off-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
> ---
> This is the kernel trace this commit fixes:
> [   29.270685] BUG: scheduling while atomic: kworker/u3:0/55/0x00000002

I just hit this bug with 6.7-rc2, I think it would be worth to
apply this fix.


[   70.443965] BUG: scheduling while atomic: kworker/u5:0/65/0x00000002
[   70.450649] Modules linked in: 8021q garp mrp stp llc usb_f_ncm u_ether spidev mwifiex_sdio mwifiex snd_soc_simple_card snd_soc_simple_card_utils crct10dif_ce cfg80211 k3_j72xx_bandgap rti_wdt rtc_ti_k3 btnxpuart bluetooth ecdh_generic ecc snd_soc_davinci_mcasp sa2ul sha256_generic rfkill snd_soc_ti_udma libsha256 snd_soc_ti_edma authenc tidss snd_soc_ti_sdma omap_mailbox drm_dma_helper ti_ads1015 industrialio_triggered_buffer lontium_lt8912b snd_soc_wm8904 kfifo_buf lm75 at24 tps65219_pwrbutton ina2xx m_can_platform rtc_ds1307 tc358768 m_can display_connector spi_omap2_mcspi pwm_tiehrpwm can_dev drm_kms_helper libcomposite fuse drm backlight ipv6
[   70.509384] CPU: 0 PID: 65 Comm: kworker/u5:0 Not tainted 6.7.0-rc2-00147-gf1a09972a45a #1
[   70.517747] Hardware name: Toradex Verdin AM62 WB on Dahlia Board (DT)
[   70.524334] Workqueue: hci0 hci_power_on [bluetooth]
[   70.529870] Call trace:
[   70.532349]  dump_backtrace+0x94/0xec
[   70.536103]  show_stack+0x18/0x24
[   70.539491]  dump_stack_lvl+0x48/0x60
[   70.543210]  dump_stack+0x18/0x24
[   70.546575]  __schedule_bug+0x50/0x68
[   70.550312]  __schedule+0x7c4/0xa64
[   70.553874]  schedule+0x34/0xa0
[   70.557083]  schedule_timeout+0x180/0x25c
[   70.561151]  wait_for_completion_timeout+0x80/0x15c
[   70.566101]  ti_sci_set_device_state+0x164/0x22c
[   70.570790]  ti_sci_cmd_get_device_exclusive+0x18/0x24
[   70.575991]  ti_sci_pd_power_on+0x28/0x48
[   70.580073]  _genpd_power_on+0x94/0x154
[   70.583964]  genpd_power_on.part.0+0xa4/0x174
[   70.588383]  genpd_runtime_resume+0x118/0x294
[   70.592800]  __rpm_callback+0x48/0x140
[   70.596616]  rpm_callback+0x6c/0x78
[   70.600165]  rpm_resume+0x3bc/0x59c
[   70.603714]  __pm_runtime_resume+0x4c/0x90
[   70.607870]  omap8250_set_mctrl+0x2c/0xc0
[   70.611954]  serial8250_set_mctrl.part.0+0x18/0x34
[   70.616801]  serial8250_set_mctrl+0x18/0x28
[   70.621038]  uart_update_mctrl+0x58/0x78
[   70.625024]  uart_dtr_rts+0x108/0x118
[   70.628750]  tty_port_shutdown+0x88/0xd8
[   70.632744]  tty_port_close+0x50/0xac
[   70.636472]  uart_close+0x28/0x80
[   70.639850]  ttyport_close+0x50/0x94
[   70.643500]  serdev_device_close+0x40/0x50
[   70.647664]  btnxpuart_close+0x24/0x84 [btnxpuart]
[   70.652553]  hci_dev_open_sync+0x3f8/0x9dc [bluetooth]
[   70.658144]  hci_dev_do_open+0x28/0x48 [bluetooth]
[   70.663377]  hci_power_on+0x4c/0x2ac [bluetooth]
[   70.668441]  process_scheduled_works+0x16c/0x28c
[   70.673135]  worker_thread+0x16c/0x2e0
[   70.676950]  kthread+0x11c/0x128
[   70.680247]  ret_from_fork+0x10/0x20