Commit 3be60b56 authored by Jeffrey Hugo's avatar Jeffrey Hugo Committed by Martin K. Petersen
Browse files

scsi: ufs-qcom: Fix scheduling while atomic issue 

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().

Link: https://lore.kernel.org/r/20200525204125.46171-1-jeffrey.l.hugo@gmail.com


Fixes: 9c46b867 ("scsi: ufs-qcom: dump additional testbus registers")
Reviewed-by: default avatarBean Huo <beanhuo@micron.com>
Reviewed-by: default avatarAvri Altman <avri.altman@wdc.com>
Signed-off-by: default avatarJeffrey Hugo <jeffrey.l.hugo@gmail.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent f56577e8

drivers/scsi/ufs/ufs-qcom.c

+3 −3
Original line number Diff line number Diff line
@@ -1658,11 +1658,11 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba) 


	/* sleep a bit intermittently as we are dumping too much data */

	ufs_qcom_print_hw_debug_reg_all(hba, NULL, ufs_qcom_dump_regs_wrapper);

	usleep_range(1000, 1100);

	udelay(1000);

	ufs_qcom_testbus_read(hba);

	usleep_range(1000, 1100);

	udelay(1000);

	ufs_qcom_print_unipro_testbus(hba);

	usleep_range(1000, 1100);

	udelay(1000);

}



/**