UART getting panic while doing echo

Cyriactoms — Thu, 08 Jan 2026 06:31:16 GMT

root@imx8mp-lpddr4-evk:~# echo "test" > /dev/ttymxc0
[ 31.839716] imx-uart 30860000.serial: We cannot prepare for the RX slave dma!
[ 31.847031] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 31.855822] Mem abort info:
[ 31.858616] ESR = 0x96000044
[ 31.861669] EC = 0x25: DABT (current EL), IL = 32 bits
[ 31.866980] SET = 0, FnV = 0
[ 31.870031] EA = 0, S1PTW = 0
[ 31.873173] FSC = 0x04: level 0 translation fault
[ 31.878047] Data abort info:
[ 31.880928] ISV = 0, ISS = 0x00000044
[ 31.884762] CM = 0, WnR = 1
[ 31.887729] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000106935000
[ 31.894167] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[ 31.900961] Internal error: Oops: 96000044 [#1] PREEMPT SMP
[ 31.906534] Modules linked in: fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine authenc libdes imx8_media_dev(C) dw_hdmi_cec snd_soc_fsl_xcvr snd_soc_fsl_easrc snd_soc_fsl_asrc snd_soc_fsl_aud2htx snd_soc_fsl_sai snd_soc_wm8960 caam secvio error flexcan can_dev snd_soc_fsl_asoc_card crct10dif_ce snd_soc_imx_audmux snd_soc_imx_card snd_soc_imx_hdmi fuse
[ 31.940204] CPU: 3 PID: 403 Comm: sh Tainted: G C 5.15.71+g95448dd0dc9b #1
[ 31.948383] Hardware name: NXP i.MX8MPlus EVK board (DT)
[ 31.953694] pstate: 800000c5 (Nzcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 31.960654] pc : sdma_transfer_init+0x110/0x23c
[ 31.965194] lr : sdma_transfer_init+0xc4/0x23c
[ 31.969640] sp : ffff80000acfba10
[ 31.972951] x29: ffff80000acfba10 x28: 0000000000000000 x27: ffff0000c0e046b0
[ 31.980093] x26: ffff0000c6e8db00 x25: 00000000000002ed x24: 00000000000000c0
[ 31.987235] x23: 0000000000000000 x22: ffff800009e2d200 x21: 0000000000000080
[ 31.994376] x20: ffff0000c0e00080 x19: ffff0000c0e008c8 x18: ffff800009dc0c6c
[ 32.001516] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000022
[ 32.008657] x14: 0000000000000001 x13: 001fffffffffffff x12: 0000000000002000
[ 32.015800] x11: 0000000000000006 x10: 00000000ffffffff x9 : 0000000000000000
[ 32.022939] x8 : ffff800009e2d280 x7 : 0000000000000000 x6 : 000000000000003f
[ 32.030079] x5 : 0000000000000040 x4 : 0000000000000000 x3 : 0000000000000004
[ 32.037219] x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000001830020
[ 32.044363] Call trace:
[ 32.046809] sdma_transfer_init+0x110/0x23c
[ 32.050997] sdma_prep_slave_sg+0x7c/0x2c0
[ 32.055096] imx_uart_dma_tx+0xdc/0x230
[ 32.058935] imx_uart_start_tx+0x10c/0x200
[ 32.063032] __uart_start.isra.0+0x3c/0x4c
[ 32.067132] uart_write+0xfc/0x86c
[ 32.070534] do_output_char+0x178/0x1a4
[ 32.074372] n_tty_write+0x168/0x46c
[ 32.077949] file_tty_write.constprop.0+0x130/0x294
[ 32.082829] tty_write+0x14/0x20
[ 32.086058] new_sync_write+0xe8/0x184
[ 32.089813] vfs_write+0x22c/0x290
[ 32.093213] ksys_write+0x68/0xf4
[ 32.096530] __arm64_sys_write+0x1c/0x2c
[ 32.100454] invoke_syscall+0x48/0x114
[ 32.104206] el0_svc_common.constprop.0+0xd4/0xfc
[ 32.108910] do_el0_svc+0x28/0x90
[ 32.112226] el0_svc+0x28/0x80
[ 32.115284] el0t_64_sync_handler+0xa4/0x130
[ 32.119560] el0t_64_sync+0x1a0/0x1a4
[ 32.123227] Code: b90026c0 52800400 531b6ab5 72a03060 (b90002e0)
[ 32.129320] ---[ end trace 6a285478727e1a53 ]---
[ 32.133937] note: sh[403] exited with preempt_count 2

I am getting panic error while doing echo in all the uart

i am using kernel 5.15.71

Re: UART getting panic while doing echo

joanxie — Sat, 10 Jan 2026 03:25:11 GMT

did you use nxp evk board? I couldn't reproduce this on 6.12 bsp, do you mind upgrading the bsp and test again?

topic Re: UART getting panic while doing echo in Other NXP Products

UART getting panic while doing echo

Re: UART getting panic while doing echo