kernel/linux.git/drivers/tty/serial, branch v4.4.239

tty: serial: samsung: Correct clock selection logic

2020-10-01T09:11:55+00:00

[ Upstream commit 7d31676a8d91dd18e08853efd1cb26961a38c6a6 ] Some variants of the samsung tty driver can pick which clock to use for their baud rate generation. In the DT conversion, a default clock was selected to be used if a specific one wasn't assigned and then a comparison of which clock rate worked better was done. Unfortunately, the comparison was implemented in such a way that only the default clock was ever actually compared. Fix this by iterating through all possible clocks, except when a specific clock has already been picked via clk_sel (which is only possible via board files). Signed-off-by: Jonathan Bakker Reviewed-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/BN6PR04MB06604E63833EA41837EBF77BA3A30@BN6PR04MB0660.namprd04.prod.outlook.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250_omap: Fix sleeping function called from invalid context during probe

2020-10-01T09:11:54+00:00

[ Upstream commit 4ce35a3617c0ac758c61122b2218b6c8c9ac9398 ] When booting j721e the following bug is printed: [ 1.154821] BUG: sleeping function called from invalid context at kernel/sched/completion.c:99 [ 1.154827] in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 12, name: kworker/0:1 [ 1.154832] 3 locks held by kworker/0:1/12: [ 1.154836] #0: ffff000840030728 ((wq_completion)events){+.+.}, at: process_one_work+0x1d4/0x6e8 [ 1.154852] #1: ffff80001214fdd8 (deferred_probe_work){+.+.}, at: process_one_work+0x1d4/0x6e8 [ 1.154860] #2: ffff00084060b170 (&dev->mutex){....}, at: __device_attach+0x38/0x138 [ 1.154872] irq event stamp: 63096 [ 1.154881] hardirqs last enabled at (63095): [] _raw_spin_unlock_irqrestore+0x70/0x78 [ 1.154887] hardirqs last disabled at (63096): [] _raw_spin_lock_irqsave+0x28/0x80 [ 1.154893] softirqs last enabled at (62254): [] _stext+0x488/0x564 [ 1.154899] softirqs last disabled at (62247): [] irq_exit+0x114/0x140 [ 1.154906] CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.6.0-rc6-next-20200318-00094-g45e4089b0bd3 #221 [ 1.154911] Hardware name: Texas Instruments K3 J721E SoC (DT) [ 1.154917] Workqueue: events deferred_probe_work_func [ 1.154923] Call trace: [ 1.154928] dump_backtrace+0x0/0x190 [ 1.154933] show_stack+0x14/0x20 [ 1.154940] dump_stack+0xe0/0x148 [ 1.154946] ___might_sleep+0x150/0x1f0 [ 1.154952] __might_sleep+0x4c/0x80 [ 1.154957] wait_for_completion_timeout+0x40/0x140 [ 1.154964] ti_sci_set_device_state+0xa0/0x158 [ 1.154969] ti_sci_cmd_get_device_exclusive+0x14/0x20 [ 1.154977] ti_sci_dev_start+0x34/0x50 [ 1.154984] genpd_runtime_resume+0x78/0x1f8 [ 1.154991] __rpm_callback+0x3c/0x140 [ 1.154996] rpm_callback+0x20/0x80 [ 1.155001] rpm_resume+0x568/0x758 [ 1.155007] __pm_runtime_resume+0x44/0xb0 [ 1.155013] omap8250_probe+0x2b4/0x508 [ 1.155019] platform_drv_probe+0x50/0xa0 [ 1.155023] really_probe+0xd4/0x318 [ 1.155028] driver_probe_device+0x54/0xe8 [ 1.155033] __device_attach_driver+0x80/0xb8 [ 1.155039] bus_for_each_drv+0x74/0xc0 [ 1.155044] __device_attach+0xdc/0x138 [ 1.155049] device_initial_probe+0x10/0x18 [ 1.155053] bus_probe_device+0x98/0xa0 [ 1.155058] deferred_probe_work_func+0x74/0xb0 [ 1.155063] process_one_work+0x280/0x6e8 [ 1.155068] worker_thread+0x48/0x430 [ 1.155073] kthread+0x108/0x138 [ 1.155079] ret_from_fork+0x10/0x18 To fix the bug we need to first call pm_runtime_enable() prior to any pm_runtime calls. Reported-by: Tomi Valkeinen Signed-off-by: Peter Ujfalusi Link: https://lore.kernel.org/r/20200320125200.6772-1-peter.ujfalusi@ti.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250: Avoid error message on reprobe

2020-10-01T09:11:50+00:00

commit e0a851fe6b9b619527bd928aa93caaddd003f70c upstream. If the call to uart_add_one_port() in serial8250_register_8250_port() fails, a half-initialized entry in the serial_8250ports[] array is left behind. A subsequent reprobe of the same serial port causes that entry to be reused. Because uart->port.dev is set, uart_remove_one_port() is called for the half-initialized entry and bails out with an error message: bcm2835-aux-uart 3f215040.serial: Removing wrong port: (null) != (ptrval) The same happens on failure of mctrl_gpio_init() since commit 4a96895f74c9 ("tty/serial/8250: use mctrl_gpio helpers"). Fix by zeroing the uart->port.dev pointer in the probe error path. The bug was introduced in v2.6.10 by historical commit befff6f5bf5f ("[SERIAL] Add new port registration/unregistration functions."): https://git.kernel.org/tglx/history/c/befff6f5bf5f The commit added an unconditional call to uart_remove_one_port() in serial8250_register_port(). In v3.7, commit 835d844d1a28 ("8250_pnp: do pnp probe before legacy probe") made that call conditional on uart->port.dev which allows me to fix the issue by zeroing that pointer in the error path. Thus, the present commit will fix the problem as far back as v3.7 whereas still older versions need to also cherry-pick 835d844d1a28. Fixes: 835d844d1a28 ("8250_pnp: do pnp probe before legacy probe") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v2.6.10 Cc: stable@vger.kernel.org # v2.6.10: 835d844d1a28: 8250_pnp: do pnp probe before legacy Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/b4a072013ee1a1d13ee06b4325afb19bda57ca1b.1589285873.git.lukas@wunner.de [iwamatsu: Backported to 4.4, 4.9: adjust context] Signed-off-by: Nobuhiro Iwamatsu (CIP) Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: Add Realtek 816a and 816b

2020-09-23T06:44:27+00:00

commit 3c5a87be170aba8ac40982182f812dcff6ed1ad1 upstream. These serial ports are exposed by the OOB-management-engine on RealManage-enabled network cards (e.g. AMD DASH enabled systems using Realtek cards). Because these have 3 BARs, they fail the "num_iomem <= 1" check in serial_pci_guess_board. I've manually checked the two IOMEM regions and BAR 2 doesn't seem to respond to reads, but BAR 4 seems to be an MMIO version of the IO ports (untested). With this change, the ports are detected: 0000:02:00.1: ttyS0 at I/O 0x2200 (irq = 82, base_baud = 115200) is a 16550A 0000:02:00.2: ttyS1 at I/O 0x2100 (irq = 55, base_baud = 115200) is a 16550A lspci output: 02:00.1 0700: 10ec:816a (rev 0e) (prog-if 02 [16550]) Subsystem: 17aa:5082 Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort+ SERR- Cc: stable Link: https://lore.kernel.org/r/20200914173628.GA22508@yamamaya.is-a-geek.org Signed-off-by: Greg Kroah-Hartman

serial: 8250: change lock order in serial8250_do_startup()

2020-09-03T09:19:26+00:00

commit 205d300aea75623e1ae4aa43e0d265ab9cf195fd upstream. We have a number of "uart.port->desc.lock vs desc.lock->uart.port" lockdep reports coming from 8250 driver; this causes a bit of trouble to people, so let's fix it. The problem is reverse lock order in two different call paths: chain #1: serial8250_do_startup() spin_lock_irqsave(&port->lock); disable_irq_nosync(port->irq); raw_spin_lock_irqsave(&desc->lock) chain #2: __report_bad_irq() raw_spin_lock_irqsave(&desc->lock) for_each_action_of_desc() printk() spin_lock_irqsave(&port->lock); Fix this by changing the order of locks in serial8250_do_startup(): do disable_irq_nosync() first, which grabs desc->lock, and grab uart->port after that, so that chain #1 and chain #2 have same lock order. Full lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.4.39 #55 Not tainted ====================================================== swapper/0/0 is trying to acquire lock: ffffffffab65b6c0 (console_owner){-...}, at: console_lock_spinning_enable+0x31/0x57 but task is already holding lock: ffff88810a8e34c0 (&irq_desc_lock_class){-.-.}, at: __report_bad_irq+0x5b/0xba which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&irq_desc_lock_class){-.-.}: _raw_spin_lock_irqsave+0x61/0x8d __irq_get_desc_lock+0x65/0x89 __disable_irq_nosync+0x3b/0x93 serial8250_do_startup+0x451/0x75c uart_startup+0x1b4/0x2ff uart_port_activate+0x73/0xa0 tty_port_open+0xae/0x10a uart_open+0x1b/0x26 tty_open+0x24d/0x3a0 chrdev_open+0xd5/0x1cc do_dentry_open+0x299/0x3c8 path_openat+0x434/0x1100 do_filp_open+0x9b/0x10a do_sys_open+0x15f/0x3d7 kernel_init_freeable+0x157/0x1dd kernel_init+0xe/0x105 ret_from_fork+0x27/0x50 -> #1 (&port_lock_key){-.-.}: _raw_spin_lock_irqsave+0x61/0x8d serial8250_console_write+0xa7/0x2a0 console_unlock+0x3b7/0x528 vprintk_emit+0x111/0x17f printk+0x59/0x73 register_console+0x336/0x3a4 uart_add_one_port+0x51b/0x5be serial8250_register_8250_port+0x454/0x55e dw8250_probe+0x4dc/0x5b9 platform_drv_probe+0x67/0x8b really_probe+0x14a/0x422 driver_probe_device+0x66/0x130 device_driver_attach+0x42/0x5b __driver_attach+0xca/0x139 bus_for_each_dev+0x97/0xc9 bus_add_driver+0x12b/0x228 driver_register+0x64/0xed do_one_initcall+0x20c/0x4a6 do_initcall_level+0xb5/0xc5 do_basic_setup+0x4c/0x58 kernel_init_freeable+0x13f/0x1dd kernel_init+0xe/0x105 ret_from_fork+0x27/0x50 -> #0 (console_owner){-...}: __lock_acquire+0x118d/0x2714 lock_acquire+0x203/0x258 console_lock_spinning_enable+0x51/0x57 console_unlock+0x25d/0x528 vprintk_emit+0x111/0x17f printk+0x59/0x73 __report_bad_irq+0xa3/0xba note_interrupt+0x19a/0x1d6 handle_irq_event_percpu+0x57/0x79 handle_irq_event+0x36/0x55 handle_fasteoi_irq+0xc2/0x18a do_IRQ+0xb3/0x157 ret_from_intr+0x0/0x1d cpuidle_enter_state+0x12f/0x1fd cpuidle_enter+0x2e/0x3d do_idle+0x1ce/0x2ce cpu_startup_entry+0x1d/0x1f start_kernel+0x406/0x46a secondary_startup_64+0xa4/0xb0 other info that might help us debug this: Chain exists of: console_owner --> &port_lock_key --> &irq_desc_lock_class Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&irq_desc_lock_class); lock(&port_lock_key); lock(&irq_desc_lock_class); lock(console_owner); *** DEADLOCK *** 2 locks held by swapper/0/0: #0: ffff88810a8e34c0 (&irq_desc_lock_class){-.-.}, at: __report_bad_irq+0x5b/0xba #1: ffffffffab65b5c0 (console_lock){+.+.}, at: console_trylock_spinning+0x20/0x181 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.39 #55 Hardware name: XXXXXX Call Trace: dump_stack+0xbf/0x133 ? print_circular_bug+0xd6/0xe9 check_noncircular+0x1b9/0x1c3 __lock_acquire+0x118d/0x2714 lock_acquire+0x203/0x258 ? console_lock_spinning_enable+0x31/0x57 console_lock_spinning_enable+0x51/0x57 ? console_lock_spinning_enable+0x31/0x57 console_unlock+0x25d/0x528 ? console_trylock+0x18/0x4e vprintk_emit+0x111/0x17f ? lock_acquire+0x203/0x258 printk+0x59/0x73 __report_bad_irq+0xa3/0xba note_interrupt+0x19a/0x1d6 handle_irq_event_percpu+0x57/0x79 handle_irq_event+0x36/0x55 handle_fasteoi_irq+0xc2/0x18a do_IRQ+0xb3/0x157 common_interrupt+0xf/0xf Signed-off-by: Sergey Senozhatsky Fixes: 768aec0b5bcc ("serial: 8250: fix shared interrupts issues with SMP and RT kernels") Reported-by: Guenter Roeck Reported-by: Raul Rangel BugLink: https://bugs.chromium.org/p/chromium/issues/detail?id=1114800 Link: https://lore.kernel.org/lkml/CAHQZ30BnfX+gxjPm1DUd5psOTqbyDh4EJE=2=VAMW_VDafctkA@mail.gmail.com/T/#u Reviewed-by: Andy Shevchenko Reviewed-by: Guenter Roeck Tested-by: Guenter Roeck Cc: stable Link: https://lore.kernel.org/r/20200817022646.1484638-1-sergey.senozhatsky@gmail.com Signed-off-by: Greg Kroah-Hartman

serial: pl011: Don't leak amba_ports entry on driver register error

2020-09-03T09:19:26+00:00

commit 89efbe70b27dd325d8a8c177743a26b885f7faec upstream. pl011_probe() calls pl011_setup_port() to reserve an amba_ports[] entry, then calls pl011_register_port() to register the uart driver with the tty layer. If registration of the uart driver fails, the amba_ports[] entry is not released. If this happens 14 times (value of UART_NR macro), then all amba_ports[] entries will have been leaked and driver probing is no longer possible. (To be fair, that can only happen if the DeviceTree doesn't contain alias IDs since they cause the same entry to be used for a given port.) Fix it. Fixes: ef2889f7ffee ("serial: pl011: Move uart_register_driver call to device") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v3.15+ Cc: Tushar Behera Link: https://lore.kernel.org/r/138f8c15afb2f184d8102583f8301575566064a6.1597316167.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

serial: samsung: Removes the IRQ not found warning

2020-09-03T09:19:26+00:00

commit 8c6c378b0cbe0c9f1390986b5f8ffb5f6ff7593b upstream. In few older Samsung SoCs like s3c2410, s3c2412 and s3c2440, UART IP is having 2 interrupt lines. However, in other SoCs like s3c6400, s5pv210, exynos5433, and exynos4210 UART is having only 1 interrupt line. Due to this, "platform_get_irq(platdev, 1)" call in the driver gives the following false-positive error: "IRQ index 1 not found" on newer SoC's. This patch adds the condition to check for Tx interrupt only for the those SoC's which have 2 interrupt lines. Tested-by: Alim Akhtar Tested-by: Marek Szyprowski Reviewed-by: Krzysztof Kozlowski Reviewed-by: Alim Akhtar Signed-off-by: Tamseel Shams Cc: stable Link: https://lore.kernel.org/r/20200810030021.45348-1-m.shams@samsung.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_mtk: Fix high-speed baud rates clamping

2020-07-31T14:43:15+00:00

commit 551e553f0d4ab623e2a6f424ab5834f9c7b5229c upstream. Commit 7b668c064ec3 ("serial: 8250: Fix max baud limit in generic 8250 port") fixed limits of a baud rate setting for a generic 8250 port. In other words since that commit the baud rate has been permitted to be within [uartclk / 16 / UART_DIV_MAX; uartclk / 16], which is absolutely normal for a standard 8250 UART port. But there are custom 8250 ports, which provide extended baud rate limits. In particular the Mediatek 8250 port can work with baud rates up to "uartclk" speed. Normally that and any other peculiarity is supposed to be handled in a custom set_termios() callback implemented in the vendor-specific 8250-port glue-driver. Currently that is how it's done for the most of the vendor-specific 8250 ports, but for some reason for Mediatek a solution has been spread out to both the glue-driver and to the generic 8250-port code. Due to that a bug has been introduced, which permitted the extended baud rate limit for all even for standard 8250-ports. The bug has been fixed by the commit 7b668c064ec3 ("serial: 8250: Fix max baud limit in generic 8250 port") by narrowing the baud rates limit back down to the normal bounds. Unfortunately by doing so we also broke the Mediatek-specific extended bauds feature. A fix of the problem described above is twofold. First since we can't get back the extended baud rate limits feature to the generic set_termios() function and that method supports only a standard baud rates range, the requested baud rate must be locally stored before calling it and then restored back to the new termios structure after the generic set_termios() finished its magic business. By doing so we still use the serial8250_do_set_termios() method to set the LCR/MCR/FCR/etc. registers, while the extended baud rate setting procedure will be performed later in the custom Mediatek-specific set_termios() callback. Second since a true baud rate is now fully calculated in the custom set_termios() method we need to locally update the port timeout by calling the uart_update_timeout() function. After the fixes described above are implemented in the 8250_mtk.c driver, the Mediatek 8250-port should get back to normally working with extended baud rates. Link: https://lore.kernel.org/linux-serial/20200701211337.3027448-1-danielwinkler@google.com Fixes: 7b668c064ec3 ("serial: 8250: Fix max baud limit in generic 8250 port") Reported-by: Daniel Winkler Signed-off-by: Serge Semin Cc: stable Tested-by: Claire Chang Link: https://lore.kernel.org/r/20200714124113.20918-1-Sergey.Semin@baikalelectronics.ru Signed-off-by: Greg Kroah-Hartman

serial: 8250: fix null-ptr-deref in serial8250_start_tx()

2020-07-31T14:43:14+00:00

commit f4c23a140d80ef5e6d3d1f8f57007649014b60fa upstream. I got null-ptr-deref in serial8250_start_tx(): [ 78.114630] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 78.123778] Mem abort info: [ 78.126560] ESR = 0x86000007 [ 78.129603] EC = 0x21: IABT (current EL), IL = 32 bits [ 78.134891] SET = 0, FnV = 0 [ 78.137933] EA = 0, S1PTW = 0 [ 78.141064] user pgtable: 64k pages, 48-bit VAs, pgdp=00000027d41a8600 [ 78.147562] [0000000000000000] pgd=00000027893f0003, p4d=00000027893f0003, pud=00000027893f0003, pmd=00000027c9a20003, pte=0000000000000000 [ 78.160029] Internal error: Oops: 86000007 [#1] SMP [ 78.164886] Modules linked in: sunrpc vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce ses enclosure sg sbsa_gwdt ipmi_ssif spi_dw_mmio sch_fq_codel vhost_net tun vhost vhost_iotlb tap ip_tables ext4 mbcache jbd2 ahci hisi_sas_v3_hw libahci hisi_sas_main libsas hns3 scsi_transport_sas hclge libata megaraid_sas ipmi_si hnae3 ipmi_devintf ipmi_msghandler br_netfilter bridge stp llc nvme nvme_core xt_sctp sctp libcrc32c dm_mod nbd [ 78.207383] CPU: 11 PID: 23258 Comm: null-ptr Not tainted 5.8.0-rc6+ #48 [ 78.214056] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B210.01 03/12/2020 [ 78.222888] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--) [ 78.228435] pc : 0x0 [ 78.230618] lr : serial8250_start_tx+0x160/0x260 [ 78.235215] sp : ffff800062eefb80 [ 78.238517] x29: ffff800062eefb80 x28: 0000000000000fff [ 78.243807] x27: ffff800062eefd80 x26: ffff202fd83b3000 [ 78.249098] x25: ffff800062eefd80 x24: ffff202fd83b3000 [ 78.254388] x23: ffff002fc5e50be8 x22: 0000000000000002 [ 78.259679] x21: 0000000000000001 x20: 0000000000000000 [ 78.264969] x19: ffffa688827eecc8 x18: 0000000000000000 [ 78.270259] x17: 0000000000000000 x16: 0000000000000000 [ 78.275550] x15: ffffa68881bc67a8 x14: 00000000000002e6 [ 78.280841] x13: ffffa68881bc67a8 x12: 000000000000c539 [ 78.286131] x11: d37a6f4de9bd37a7 x10: ffffa68881cccff0 [ 78.291421] x9 : ffffa68881bc6000 x8 : ffffa688819daa88 [ 78.296711] x7 : ffffa688822a0f20 x6 : ffffa688819e0000 [ 78.302002] x5 : ffff800062eef9d0 x4 : ffffa68881e707a8 [ 78.307292] x3 : 0000000000000000 x2 : 0000000000000002 [ 78.312582] x1 : 0000000000000001 x0 : ffffa688827eecc8 [ 78.317873] Call trace: [ 78.320312] 0x0 [ 78.322147] __uart_start.isra.9+0x64/0x78 [ 78.326229] uart_start+0xb8/0x1c8 [ 78.329620] uart_flush_chars+0x24/0x30 [ 78.333442] n_tty_receive_buf_common+0x7b0/0xc30 [ 78.338128] n_tty_receive_buf+0x44/0x2c8 [ 78.342122] tty_ioctl+0x348/0x11f8 [ 78.345599] ksys_ioctl+0xd8/0xf8 [ 78.348903] __arm64_sys_ioctl+0x2c/0xc8 [ 78.352812] el0_svc_common.constprop.2+0x88/0x1b0 [ 78.357583] do_el0_svc+0x44/0xd0 [ 78.360887] el0_sync_handler+0x14c/0x1d0 [ 78.364880] el0_sync+0x140/0x180 [ 78.368185] Code: bad PC value SERIAL_PORT_DFNS is not defined on each arch, if it's not defined, serial8250_set_defaults() won't be called in serial8250_isa_init_ports(), so the p->serial_in pointer won't be initialized, and it leads a null-ptr-deref. Fix this problem by calling serial8250_set_defaults() after init uart port. Signed-off-by: Yang Yingliang Cc: stable Link: https://lore.kernel.org/r/20200721143852.4058352-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman

serial: amba-pl011: Make sure we initialize the port.lock spinlock

2020-06-30T00:07:50+00:00

[ Upstream commit 8508f4cba308f785b2fd4b8c38849c117b407297 ] Valentine reported seeing: [ 3.626638] INFO: trying to register non-static key. [ 3.626639] the code is fine but needs lockdep annotation. [ 3.626640] turning off the locking correctness validator. [ 3.626644] CPU: 7 PID: 51 Comm: kworker/7:1 Not tainted 5.7.0-rc2-00115-g8c2e9790f196 #116 [ 3.626646] Hardware name: HiKey960 (DT) [ 3.626656] Workqueue: events deferred_probe_work_func [ 3.632476] sd 0:0:0:0: [sda] Optimal transfer size 8192 bytes not a multiple of physical block size (16384 bytes) [ 3.640220] Call trace: [ 3.640225] dump_backtrace+0x0/0x1b8 [ 3.640227] show_stack+0x20/0x30 [ 3.640230] dump_stack+0xec/0x158 [ 3.640234] register_lock_class+0x598/0x5c0 [ 3.640235] __lock_acquire+0x80/0x16c0 [ 3.640236] lock_acquire+0xf4/0x4a0 [ 3.640241] _raw_spin_lock_irqsave+0x70/0xa8 [ 3.640245] uart_add_one_port+0x388/0x4b8 [ 3.640248] pl011_register_port+0x70/0xf0 [ 3.640250] pl011_probe+0x184/0x1b8 [ 3.640254] amba_probe+0xdc/0x180 [ 3.640256] really_probe+0xe0/0x338 [ 3.640257] driver_probe_device+0x60/0xf8 [ 3.640259] __device_attach_driver+0x8c/0xd0 [ 3.640260] bus_for_each_drv+0x84/0xd8 [ 3.640261] __device_attach+0xe4/0x140 [ 3.640263] device_initial_probe+0x1c/0x28 [ 3.640265] bus_probe_device+0xa4/0xb0 [ 3.640266] deferred_probe_work_func+0x7c/0xb8 [ 3.640269] process_one_work+0x2c0/0x768 [ 3.640271] worker_thread+0x4c/0x498 [ 3.640272] kthread+0x14c/0x158 [ 3.640275] ret_from_fork+0x10/0x1c Which seems to be due to the fact that after allocating the uap structure, nothing initializes the spinlock. Its a little confusing, as uart_port_spin_lock_init() is one place where the lock is supposed to be initialized, but it has an exception for the case where the port is a console. This makes it seem like a deeper fix is needed to properly register the console, but I'm not sure what that entails, and Andy suggested that this approach is less invasive. Thus, this patch resolves the issue by initializing the spinlock in the driver, and resolves the resulting warning. Cc: Andy Shevchenko Cc: Russell King Cc: Jiri Slaby Cc: linux-serial@vger.kernel.org Reported-by: Valentin Schneider Reviewed-by: Andy Shevchenko Signed-off-by: John Stultz Reviewed-and-tested-by: Valentin Schneider Link: https://lore.kernel.org/r/20200428184050.6501-1-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin