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Commit 6f818221 authored by Subhash Jadavani's avatar Subhash Jadavani
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scsi: ufs-msm: disable the sigdet before power collapsing PHY 



If UFS PHY power down is deasserted and power is restored to analog
circuits, the rx_sigdet can glitch. If the glitch is wide enough,
it can trigger the PHY digital logic to think it saw a DIF-N and
cause it to exit Hibern8. Disabling the rx_sigdet during power-up
will mask the glitch.

Change-Id: I20d93d2f5b479bb9e1d9626cfb9939d280b172a5
Signed-off-by: default avatarSubhash Jadavani <subhashj@codeaurora.org>
parent ee794fa1

drivers/scsi/ufs/ufs-msm.c

+39 −10
Original line number Diff line number Diff line
@@ -1855,13 +1855,6 @@ static int msm_ufs_phy_power_on(struct msm_ufs_phy *phy) 
	if (err)

		goto out;



	writel_relaxed(0x1, phy->mmio + UFS_PHY_POWER_DOWN_CONTROL);

	/*

	 * Before any transactions involving PHY, ensure PHY knows that it's

	 * analog rail is powered ON.

	 */

	mb();



	/* vdda_pll also enables ref clock LDOs so enable it first */

	err = msm_ufs_phy_enable_vreg(phy, &phy->vdda_pll);

	if (err)
@@ -1871,6 +1864,20 @@ static int msm_ufs_phy_power_on(struct msm_ufs_phy *phy) 
	if (err)

		goto out_disable_pll;



	writel_relaxed(0x1, phy->mmio + UFS_PHY_POWER_DOWN_CONTROL);

	/*

	 * Before any transactions involving PHY, ensure PHY knows that it's

	 * analog rail is powered ON. This also ensures that PHY is out of

	 * power collapse before enabling the SIGDET.

	 */

	mb();

	if (phy->quirks & MSM_UFS_PHY_DIS_SIGDET_BEFORE_PWR_COLLAPSE) {

		writel_relaxed(0xC0, phy->mmio + QSERDES_RX_SIGDET_CNTRL(0));

		writel_relaxed(0xC0, phy->mmio + QSERDES_RX_SIGDET_CNTRL(1));

		/* make sure that SIGDET is enabled before proceeding further */

		mb();

	}



	goto out;



out_disable_pll:
@@ -1883,7 +1890,17 @@ out: 


static int msm_ufs_phy_power_off(struct msm_ufs_phy *phy)

{

	if (phy->quirks & MSM_UFS_PHY_DIS_SIGDET_BEFORE_PWR_COLLAPSE) {

		writel_relaxed(0x0, phy->mmio + QSERDES_RX_SIGDET_CNTRL(0));

		writel_relaxed(0x0, phy->mmio + QSERDES_RX_SIGDET_CNTRL(1));

		/* Ensure that SIGDET is disabled before PHY power collapse */

		mb();

	}

	writel_relaxed(0x0, phy->mmio + UFS_PHY_POWER_DOWN_CONTROL);

	/*

	 * Ensure that PHY knows its PHY analog rail is going to be powered

	 * down.

	 */

	mb();



	msm_ufs_disable_phy_ref_clk(phy);
@@ -2231,10 +2248,21 @@ static int msm_ufs_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) 
			msm_ufs_save_phy_configuration(hba);



		msm_ufs_disable_phy_ref_clk(phy);

		if (phy->quirks & MSM_UFS_PHY_DIS_SIGDET_BEFORE_PWR_COLLAPSE) {

			writel_relaxed(0x0,

				       phy->mmio + QSERDES_RX_SIGDET_CNTRL(0));

			writel_relaxed(0x0,

				       phy->mmio + QSERDES_RX_SIGDET_CNTRL(1));

			/*

			 * Ensure that SIGDET is disabled before PHY power

			 * collapse

			 */

			mb();

		}

		writel_relaxed(0x0, phy->mmio + UFS_PHY_POWER_DOWN_CONTROL);

		/*

		 * Ensure PHY knows that PHY analog rail is going to be powered

		 * down.

		 * Ensure that PHY knows its PHY analog rail is going to be

		 * powered down.

		 */

		mb();

		msm_ufs_phy_disable_vreg(phy, &phy->vdda_phy);
@@ -2558,7 +2586,8 @@ static void msm_ufs_advertise_quirks(struct ufs_hba *hba) 
			      | UFSHCD_QUIRK_BROKEN_PA_RXHSUNTERMCAP

			      | UFSHCD_QUIRK_BROKEN_LCC);



		phy->quirks = MSM_UFS_PHY_QUIRK_CFG_RESTORE;

		phy->quirks = (MSM_UFS_PHY_QUIRK_CFG_RESTORE

			     | MSM_UFS_PHY_DIS_SIGDET_BEFORE_PWR_COLLAPSE);

	}

}

drivers/scsi/ufs/ufs-msm.h

+8 −0
Original line number Diff line number Diff line
@@ -119,6 +119,14 @@ struct msm_ufs_phy { 
	 *	7. Wait for UFS_PHY_PCS_READY_STATUS[0] to be '1'

	 */

	#define MSM_UFS_PHY_QUIRK_CFG_RESTORE		(1 << 0)

	/*

	 * If UFS PHY power down is deasserted and power is restored to analog

	 * circuits, the rx_sigdet can glitch. If the glitch is wide enough,

	 * it can trigger the digital logic to think it saw a DIF-N and cause

	 * it to exit Hibern8. Disabling the rx_sigdet during power-up masks

	 * the glitch.

	 */

	#define MSM_UFS_PHY_DIS_SIGDET_BEFORE_PWR_COLLAPSE	(1 << 1)

};



struct msm_ufs_bus_vote {