Hi On 17.06.2020 16:39, Marcel Holtmann wrote: > From: Miao-chen Chou <mcchou@xxxxxxxxxxxx> > > This calls hci_update_background_scan() when there is any update on the > advertisement monitors. If there is at least one advertisement monitor, > the filtering policy of scan parameters should be 0x00. This also reports > device found mgmt events if there is at least one monitor. > > The following cases were tested with btmgmt advmon-* commands. > (1) add a ADV monitor and observe that the passive scanning is > triggered. > (2) remove the last ADV monitor and observe that the passive scanning is > terminated. > (3) with a LE peripheral paired, repeat (1) and observe the passive > scanning continues. > (4) with a LE peripheral paired, repeat (2) and observe the passive > scanning continues. > (5) with a ADV monitor, suspend/resume the host and observe the passive > scanning continues. > > Signed-off-by: Miao-chen Chou <mcchou@xxxxxxxxxxxx> > Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx> This patch landed recently in linux-next as commit 8208f5a9d435 ("Bluetooth: Update background scan and report device based on advertisement monitors"). It causes a regression, a kernel oops during system suspend/resume cycle on Samsung Exynos5250 based Snow Chromebook: 8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = 86c149f5 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: cmac cros_ec_sysfs cros_ec_lightbar cros_ec_debugfs cros_ec_chardev cros_ec_keyb cros_ec_dev snd_soc_hdmi_codec cros_ec_i2c cros_ec snd_soc_snow snd_soc_i2s snd_soc_idma snd_soc_s3c_dma exynosdrm analogix_dp exynos_gsc v4l2_mem2mem snd_soc_max98095 snd_soc_core ac97_bus snd_pcm_dmaengine snd_pcm snd_timer nxp_ptn3460 snd soundcore pwm_samsung spi_s3c64xx cyapatp crc_itu_t mwifiex_sdio mwifiex sha256_generic libsha256 sha256_arm btmrvl_sdio btmrvl cfg80211 bluetooth s5p_mfc governor_simpleondemand videobuf2_dma_contig videobuf2_memops videobuf2_v4l2 ecdh_generic ecc videobuf2_common videodev phy_exynos_usb2 ohci_exynos panfrost gpu_sched mc s3c2410_wdt s5p_sss s5p_cec exynos_rng rtc_s3c i2c_arb_gpio_challenge CPU: 1 PID: 16 Comm: kworker/1:0 Not tainted 5.7.0-rc7-02995-g8208f5a9d435 #8564 Hardware name: Samsung Exynos (Flattened Device Tree) Workqueue: events_freezable mmc_rescan PC is at __queue_work+0x6c/0x4e8 LR is at __queue_work+0x68/0x4e8 pc : [<c03619d8>] lr : [<c03619d4>] psr: 60000093 ... Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 6be2406a DAC: 00000051 Process kworker/1:0 (pid: 16, stack limit = 0xf9898f75) Stack: (0xee117de0 to 0xee118000) ... [<c03619d8>] (__queue_work) from [<c0361e94>] (queue_work_on+0x40/0x4c) [<c0361e94>] (queue_work_on) from [<bf17dd0c>] (hci_adv_monitors_clear+0x74/0x90 [bluetooth]) [<bf17dd0c>] (hci_adv_monitors_clear [bluetooth]) from [<bf17e138>] (hci_unregister_dev+0x158/0x224 [bluetooth]) [<bf17e138>] (hci_unregister_dev [bluetooth]) from [<bf1d1638>] (btmrvl_remove_card+0x58/0x7c [btmrvl]) [<bf1d1638>] (btmrvl_remove_card [btmrvl]) from [<c0d09698>] (sdio_bus_remove+0x30/0x11c) [<c0d09698>] (sdio_bus_remove) from [<c09d534c>] (device_release_driver_internal+0xe8/0x1ac) [<c09d534c>] (device_release_driver_internal) from [<c09d3e18>] (bus_remove_device+0xcc/0xf8) [<c09d3e18>] (bus_remove_device) from [<c09cfa3c>] (device_del+0x15c/0x384) [<c09cfa3c>] (device_del) from [<c0d098b8>] (sdio_remove_func+0x20/0x34) [<c0d098b8>] (sdio_remove_func) from [<c0d075bc>] (mmc_sdio_remove+0x38/0x64) [<c0d075bc>] (mmc_sdio_remove) from [<c0d08858>] (mmc_sdio_detect+0x6c/0xf8) [<c0d08858>] (mmc_sdio_detect) from [<c0cff6f0>] (mmc_rescan+0x1d0/0x42c) [<c0cff6f0>] (mmc_rescan) from [<c0362454>] (process_one_work+0x178/0x4ac) [<c0362454>] (process_one_work) from [<c0362b44>] (worker_thread+0x2c/0x530) [<c0362b44>] (worker_thread) from [<c0368610>] (kthread+0x12c/0x158) [<c0368610>] (kthread) from [<c03001a8>] (ret_from_fork+0x14/0x2c) Exception stack(0xee117fb0 to 0xee117ff8) ... ---[ end trace 0ec00d142e0a49cf ]--- This board uses btmrvl_sdio bluetooth driver if that helps. Reverting this commit in linux-next 20200629 'fixes' the issue. I can do more tests if needed on this hardware, just let me know how can I help and what to do. > --- > include/net/bluetooth/hci_core.h | 1 + > net/bluetooth/hci_core.c | 13 +++++++++++++ > net/bluetooth/hci_event.c | 5 +++-- > net/bluetooth/hci_request.c | 17 ++++++++++++++--- > net/bluetooth/mgmt.c | 5 ++++- > 5 files changed, 35 insertions(+), 6 deletions(-) > ... Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland