Re: [PATCH v3] net/mlx5: Flag state up only after cmdif is ready

[Paolo Abeni <pabeni@redhat.com>]

On 6/3/25 8:14 AM, Chenguang Zhao wrote:
> When driver is reloading during recovery flow, it can't get new commands
> till command interface is up again. Otherwise we may get to null pointer
> trying to access non initialized command structures.
> 
> The issue can be reproduced using the following script:
> 
> 1)Use following script to trigger PCI error.
> 
> for((i=1;i<1000;i++));
> do
> echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/reset
> echo “pci reset test $i times”
> done
> 
> 2) Use following script to read speed.
> 
> while true; do cat /sys/class/net/eth0/speed &> /dev/null; done
> 
> task: ffff885f42820fd0 ti: ffff88603f758000 task.ti: ffff88603f758000
> RIP: 0010:[] [] dma_pool_alloc+0x1ab/0×290
> RSP: 0018:ffff88603f75baf0 EFLAGS: 00010046
> RAX: 0000000000000246 RBX: ffff882f77d90c80 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 00000000000080d0 RDI: ffff882f77d90d10
> RBP: ffff88603f75bb20 R08: 0000000000019ba0 R09: ffff88017fc07c00
> R10: ffffffffc0a9c384 R11: 0000000000000246 R12: ffff882f77d90d00
> R13: 00000000000080d0 R14: ffff882f77d90d10 R15: ffff88340b6c5ea8
> FS: 00007efce8330740(0000) GS:ffff885f4da00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000000 CR3: 0000003454fc6000 CR4: 00000000003407e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call trace:
>  mlx5_alloc_cmd_msg+0xb4/0×2a0 [mlx5_core]
>  mlx5_alloc_cmd_msg+0xd3/0×2a0 [mlx5_core]
>  cmd_exec+0xcf/0×8a0 [mlx5_core]
>  mlx5_cmd_exec+0x33/0×50 [mlx5_core]
>  mlx5_core_access_reg+0xf1/0×170 [mlx5_core]
>  mlx5_query_port_ptys+0x64/0×70 [mlx5_core]
>  mlx5e_get_link_ksettings+0x5c/0×360 [mlx5_core]
>  __ethtool_get_link_ksettings+0xa6/0×210
>  speed_show+0x78/0xb0
>  dev_attr_show+0x23/0×60
>  sysfs_read_file+0x99/0×190
>  vfs_read+0x9f/0×170
>  SyS_read+0x7f/0xe0
>  tracesys+0xe3/0xe8
> 
> Fixes: a80d1b68c8b7a0 ("net/mlx5: Break load_one into three stages")
> Signed-off-by: Chenguang Zhao <zhaochenguang@kylinos.cn>

Minor nit: the 'net' tag should be in the subj prefix, alike:

[PATCH net v<n>] mlx5: #...

More importantly, please deal with Moshe feedback.

Thanks,

Paolo