Re: [PATCH] scsi: ufs: core: Avoid possible memory reclaim deadlock in TX EQTR context

[Peter Wang (王信友)]

On Tue, 2026-06-16 at 02:06 -0700, Can Guo wrote:
> TX EQTR may run while devfreq gear scaling has quiesced the UFS
> tagset. In
> that context, functions ufshcd_tx_eqtr(), __ufshcd_tx_eqtr() and
> ufs_qcom_get_rx_fom() allocate memory with GFP_KERNEL. If direct
> reclaim
> is triggered, reclaim/writeback can depend on I/O to UFS device.
> Because
> the queue is quiesced, this can cause deadlock.
> 
> Use GFP_NOIO for TX EQTR memory allocations:
> - params->eqtr_record in ufshcd_tx_eqtr()
> - eqtr_data in __ufshcd_tx_eqtr()
> - params in ufs_qcom_get_rx_fom()
> 
> Fixes: 03e5d38e2f98 ("scsi: ufs: core: Add support for TX
> Equalization")
> Closes:
> https://urldefense.com/v3/__https://sashiko.dev/*/patchset/20260615132834.2985346-1-can.guo@xxxxxxxxxxxxxxxx?part=2__;Iw!!CTRNKA9wMg0ARbw!mkZe-Src0MPmBc2cQbRZtnVJptXP26uI7g0q9gx5ARTkkm9rC-F2eyWzO_fkKvjCDwwJh7a89OZHIGvcx_KbdwM$
> Signed-off-by: Can Guo <can.guo@xxxxxxxxxxxxxxxx>
> ---

Reviewed-by: Peter Wang <peter.wang@xxxxxxxxxxxx>