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scsi: ufs-qcom: Fix scheduling while atomic issue

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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: 9c46b86762 ("scsi: ufs-qcom: dump additional testbus registers")
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Jeffrey Hugo 2020-05-25 13:41:25 -07:00 committed by Martin K. Petersen
parent f56577e8c7
commit 3be60b564d
1 changed files with 3 additions and 3 deletions
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6
drivers/scsi/ufs/ufs-qcom.c
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@ -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);
}
/**