NACK: [SRU][N][PATCH 0/1] i2c: tegra: Use internal reset when reset property is not available

[Abdur Rahman]

On 3/3/26 11:06 AM, Abdur Rahman wrote:
> [Impact]
>
> The latest Noble kernel throws warning on boot on Nvidia Grace Blackwell
> and Grace Hopper machines. The warning is thrown when device_reset is called
> on Tegra I2C device. This reset returns with error. The following is printed
> in the boot log:
> ------------[ cut here ]------------
> WARNING: CPU: 128 PID: 1248 at drivers/i2c/busses/i2c-tegra.c:622 tegra_i2c_init+0x2f4/0x3b8 [i2c_tegra]
> Modules linked in: i2c_tegra(+) fjes(-) aes_neon_bs aes_neon_blk aes_ce_blk aes_ce_cipher
> CPU: 128 PID: 1248 Comm: (udev-worker) Not tainted 6.8.0-100-generic #100-Ubuntu
> Hardware name: Supermicro MBD-G1SMH/G1SMH, BIOS 2.1a 05/27/2025
> pstate: 23400009 (nzCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
> pc : tegra_i2c_init+0x2f4/0x3b8 [i2c_tegra]
> lr : tegra_i2c_init+0x34/0x3b8 [i2c_tegra]
> sp : ffff80009a46b570
> x29: ffff80009a46b570 x28: 0000000000000000 x27: 000000000000002c
> x26: 0000000000000000 x25: 0000000000000000 x24: ffff10000c3b8068
> x23: ffff00008dcecc10 x22: ffffffffffffffed x21: ffff00008dcecc00
> x20: 0000000000000000 x19: ffff100015f65880 x18: ffff80009a3050c0
> x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
> x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
> x11: 0000000000000000 x10: 0000000000000000 x9 : ffffba296d237dc0
> x8 : ffff100008412d30 x7 : 0000000000000000 x6 : 0000000000000000
> x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
> x2 : 0000000000000000 x1 : 0000000000000000 x0 : 00000000fffffffe
> Call trace:
> tegra_i2c_init+0x2f4/0x3b8 [i2c_tegra]
> tegra_i2c_probe+0x400/0x7c8 [i2c_tegra]
> platform_probe+0x74/0x118
> really_probe+0x1c0/0x420
> __driver_probe_device+0x94/0x1d8
> driver_probe_device+0x48/0x188
> __driver_attach+0x14c/0x2c8
> bus_for_each_dev+0x88/0x110
> driver_attach+0x30/0x60
> bus_add_driver+0x17c/0x2e8
> driver_register+0x68/0x178
> __platform_driver_register+0x34/0x60
> tegra_i2c_driver_init+0x2c/0xff8 [i2c_tegra]
> do_one_initcall+0x64/0x3b8
> do_init_module+0xa4/0x280
> load_module+0x810/0x958
> init_module_from_file+0x98/0x118
> idempotent_init_module+0x200/0x308
> __arm64_sys_finit_module+0x70/0xf8
> invoke_syscall+0x7c/0x130
> el0_svc_common.constprop.0+0x4c/0x140
> do_el0_svc+0x28/0x58
> el0_svc+0x40/0x1c0
> el0t_64_sync_handler+0x148/0x158
> el0t_64_sync+0x1b0/0x1b8
> ---[ end trace 0000000000000000 ]---
>
> [Fix]
>
> Clean upstream cherry pick:
> 635bf3c88533 ("i2c: tegra: Use internal reset when reset property is not available")
>
> [Test Plan]
>
> Compile Tested. Boot warning goes away.
>
> [Where problems could occur]
>
> The scope of this patch is fairly limited and only the systems with tegra i2c
> devices can experience unexpected behavior.
>
> Akhil R (1):
>    i2c: tegra: Use internal reset when reset property is not available
>
>   drivers/i2c/busses/i2c-tegra.c | 44 +++++++++++++++++++++++++++++++++-
>   1 file changed, 43 insertions(+), 1 deletion(-)
>
Adding bug link in the v2.

Nacked-by: Abdur Rahman <abdur.rahman at canonical.com>