scsi: ufs: Make ufshcd_wait_for_register() sleep instead of busy-waiting

Browse source

The ufshcd_wait_for_register() function either sleeps or spins until the
specified register has reached the desired value. Busy-waiting is not only
considered a bad practice but also has a bad impact on energy
consumption. Always sleep instead of spinning by making sure that all
ufshcd_wait_for_register() calls happen from a context where it is allowed
to sleep. The only function call that has to be moved is the
ufshcd_hba_stop() call in ufshcd_host_reset_and_restore().

Link: https://lore.kernel.org/r/20200507222750.19113-1-bvanassche@acm.org
Cc: Can Guo <cang@codeaurora.org>
Cc: Avri Altman <avri.altman@wdc.com>
Cc: Bean Huo <beanhuo@micron.com>
Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Asutosh Das <asutoshd@codeaurora.org>
Tested-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

...

This commit is contained in:

Bart Van Assche 2020-05-07 15:27:50 -07:00 • committed by Martin K. Petersen

parent d0b1e4a638

commit 5cac1095cf

2 changed files with 29 additions and 24 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

51

drivers/scsi/ufs/ufshcd.c

View file

2

drivers/scsi/ufs/ufshcd.h

View file