v1 -> v2: replace usleep_range with udelay because it's a sleepable period. 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 | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index e096401..a772f92 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -2365,7 +2365,18 @@ 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; + ktime_t timeout = ktime_add_ms(ktime_get(), UIC_CMD_TIMEOUT); + u32 val = 0; + + do { + val = ufshcd_readl(hba, REG_CONTROLLER_STATUS) & + UIC_COMMAND_READY; + if (val) + break; + udelay(500); + } while (ktime_before(ktime_get(), timeout)); + + return val ? true : false; } /** -- 2.7.4