scsi: ufs-qcom: Delay specific time before gate ref clk (1cbadd0c) · Commits · 戴 / test

After enter hibern8, as UFS JEDEC ver 3.0 requires, a specific gating wait time is required before disable the device reference clock. If it is not specified, use the old delay. Link: https://lore.kernel.org/r/1581392451-28743-8-git-send-email-cang@codeaurora.org Reviewed-by:

drivers/scsi/ufs/ufs-qcom.c

+19 −3

Original line number	Diff line number	Diff line
		@@ -843,11 +843,27 @@ static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
		/*
		* If we are here to disable this clock it might be immediately
		* after entering into hibern8 in which case we need to make
		* sure that device ref_clk is active at least 1us after the
		* sure that device ref_clk is active for specific time after
		* hibern8 enter.
		*/
		if (!enable)
		if (!enable) {
		unsigned long gating_wait;

		gating_wait = host->hba->dev_info.clk_gating_wait_us;
		if (!gating_wait) {
		udelay(1);
		} else {
		/*
		* bRefClkGatingWaitTime defines the minimum
		* time for which the reference clock is
		* required by device during transition from
		* HS-MODE to LS-MODE or HIBERN8 state. Give it
		* more delay to be on the safe side.
		*/
		gating_wait += 10;
		usleep_range(gating_wait, gating_wait + 10);
		}
		}

		writel_relaxed(temp, host->dev_ref_clk_ctrl_mmio);