With auto hibern8 enabled, UIC could be working for a while to process a hibern8 operation and HCI reports UIC not ready for a short term through HCS.UCRDY. And UFS driver can't recognize the operation. UFSHCI spec specifies UCRDY like this: whether the host controller is ready to process UIC COMMAND The 'ready' could be seen as many different meanings. If the meaning includes not processing any request from HCI, processing a hibern8 operation can be 'not ready'. In this situation, the driver needs to wait until the operations is completed. Signed-off-by: Kiwoong Kim <kwmad.kim@xxxxxxxxxxx> --- drivers/ufs/core/ufshcd.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index a89d39a..10ccc85 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -22,6 +22,7 @@ #include <linux/module.h> #include <linux/regulator/consumer.h> #include <linux/sched/clock.h> +#include <linux/iopoll.h> #include <scsi/scsi_cmnd.h> #include <scsi/scsi_dbg.h> #include <scsi/scsi_driver.h> @@ -2365,7 +2366,11 @@ static inline int ufshcd_hba_capabilities(struct ufs_hba *hba) */ static inline bool ufshcd_ready_for_uic_cmd(struct ufs_hba *hba) { - return ufshcd_readl(hba, REG_CONTROLLER_STATUS) & UIC_COMMAND_READY; + u32 val; + int ret = read_poll_timeout(ufshcd_readl, val, val & UIC_COMMAND_READY, + 500, UIC_CMD_TIMEOUT * 1000, false, hba, + REG_CONTROLLER_STATUS); + return ret == 0 ? true : false; } /** -- 2.7.4