Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Harigovindan P <harigovi@codeaurora.org>
To:     dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org,
        freedreno@lists.freedesktop.org, devicetree@vger.kernel.org
Cc:     Harigovindan P <harigovi@codeaurora.org>,
        linux-kernel@vger.kernel.org, robdclark@gmail.com,
        seanpaul@chromium.org, hoegsberg@chromium.org,
        kalyan_t@codeaurora.org, nganji@codeaurora.org
Subject: [v1] drm/msm/dsi/pll: call vco set rate explicitly
Date:   Thu,  6 Feb 2020 14:42:01 +0530
Message-Id: <1580980321-19256-1-git-send-email-harigovi@codeaurora.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

For a given byte clock, if VCO recalc value is exactly same as
vco set rate value, vco_set_rate does not get called assuming
VCO is already set to required value. But Due to GDSC toggle,
VCO values are erased in the HW. To make sure VCO is programmed
correctly, we forcefully call set_rate from vco_prepare.

Signed-off-by: Harigovindan P <harigovi@codeaurora.org>
---

Changes in v1:
	- Calling set rate from vco_prepare

 drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c
index 1c89454..6ac04fc 100644
--- a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c
+++ b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c
@@ -411,6 +411,12 @@ static int dsi_pll_10nm_vco_prepare(struct clk_hw *hw)
 	if (pll_10nm->slave)
 		dsi_pll_enable_pll_bias(pll_10nm->slave);
 
+	rc = dsi_pll_10nm_vco_set_rate(hw,pll_10nm->vco_current_rate, 0);
+	if (rc) {
+		pr_err("vco_set_rate failed, rc=%d\n", rc);
+		return rc;
+	}
+
 	/* Start PLL */
 	pll_write(pll_10nm->phy_cmn_mmio + REG_DSI_10nm_PHY_CMN_PLL_CNTRL,
 		  0x01);
-- 
2.7.4