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[PATCH v3 09/24] drm/rockchip: dw-mipi-dsi: only request HS clock when required

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Requesting the HS clock from the PHY before we initialize it causes an
invalid signal to be sent out since the input clock is not yet
configured.  The PHY databook suggests only asserting this signal when
performing HS transfers, so let's do that.

Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Chris Zhong <zyw@rock-chips.com>
---
v3:
- Add Chris' Reviewed-by
Unchanged in v2

 drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
index 15d33c3c8cb7..03fc096fe1bd 100644
--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
@@ -545,13 +545,15 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
 static void dw_mipi_message_config(struct dw_mipi_dsi *dsi,
 				   const struct mipi_dsi_msg *msg)
 {
+	bool lpm = msg->flags & MIPI_DSI_MSG_USE_LPM;
 	u32 val = 0;
 
 	if (msg->flags & MIPI_DSI_MSG_REQ_ACK)
 		val |= EN_ACK_RQST;
-	if (msg->flags & MIPI_DSI_MSG_USE_LPM)
+	if (lpm)
 		val |= CMD_MODE_ALL_LP;
 
+	dsi_write(dsi, DSI_LPCLK_CTRL, lpm ? 0 : PHY_TXREQUESTCLKHS);
 	dsi_write(dsi, DSI_CMD_MODE_CFG, val);
 }
 
@@ -693,6 +695,7 @@ static void dw_mipi_dsi_set_mode(struct dw_mipi_dsi *dsi,
 		dsi_write(dsi, DSI_PWR_UP, RESET);
 		dsi_write(dsi, DSI_MODE_CFG, ENABLE_VIDEO_MODE);
 		dw_mipi_dsi_video_mode_config(dsi);
+		dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
 		dsi_write(dsi, DSI_PWR_UP, POWERUP);
 	}
 }
@@ -710,7 +713,6 @@ static void dw_mipi_dsi_init(struct dw_mipi_dsi *dsi)
 		  | PHY_RSTZ | PHY_SHUTDOWNZ);
 	dsi_write(dsi, DSI_CLKMGR_CFG, TO_CLK_DIVIDSION(10) |
 		  TX_ESC_CLK_DIVIDSION(7));
-	dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
 }
 
 static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
-- 
2.11.0.197.gb556de5.dirty

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[PATCH v3 09/24] drm/rockchip: dw-mipi-dsi: only request HS clock when required John Keeping <john@metanate.com> - 2017-01-29 15:10 +0100
  Re: [PATCH v3 09/24] drm/rockchip: dw-mipi-dsi: only request HS  clock when required Sean Paul <seanpaul@chromium.org> - 2017-01-30 19:30 +0100

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