Re: [PATCH] scsi: ufs-qcom: Fix scheduling while atomic issue

[Bean Huo]

On Tue, 2020-05-26 at 06:25 +0000, Avri Altman wrote:
>  
> > ufs_qcom_dump_dbg_regs() uses usleep_range, a sleeping function,
> > but can
> > be called from atomic context in the following flow:
> > 
> > ufshcd_intr -> ufshcd_sl_intr -> ufshcd_check_errors ->
> > ufshcd_print_host_regs -> ufshcd_vops_dbg_register_dump ->
> > ufs_qcom_dump_dbg_regs
> > 
> > This causes a boot crash on the Lenovo Miix 630 when the interrupt
> > is
> > handled on the idle thread.
> > 
> > Fix the issue by switching to udelay().
> > 
> > Fixes: 9c46b8676271 ("scsi: ufs-qcom: dump additional testbus
> > registers")
> > Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@xxxxxxxxx>
> 
> Reviewed-by: Avri Altman <avri.altman@xxxxxxx>
Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>