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Commit 676aec9b authored by Tony Lindgren's avatar Tony Lindgren Committed by Greg Kroah-Hartman
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drm/omap: dsi: Fix PM for display blank with paired dss_pll calls 



[ Upstream commit fe4ed1b457943113ee1138c939fbdeede4af6cf3 ]

Currently dsi_display_init_dsi() calls dss_pll_enable() but it is not
paired with dss_pll_disable() in dsi_display_uninit_dsi(). This leaves
the DSS clocks enabled when the display is blanked wasting about extra
5mW of power while idle.

The clock that is left on by not calling dss_pll_disable() is
DSS_CLKCTRL bit 10 OPTFCLKEN_SYS_CLK that is the source clock for
DSI PLL.

We can fix this issue by by making the current dsi_pll_uninit() into
dsi_pll_disable(). This way we can just call dss_pll_disable() from
dsi_display_uninit_dsi() and the code becomes a bit easier to follow.

However, we need to also consider that DSI PLL can be muxed for DVI too
as pointed out by Tomi Valkeinen <tomi.valkeinen@ti.com>. In the DVI
case, we want to unconditionally disable the clocks. To get around this
issue, we separate out the DSI lane handling from dsi_pll_enable() and
dsi_pll_disable() as suggested by Tomi in an earlier experimental patch.

So we must only toggle the DSI regulator based on the vdds_dsi_enabled
flag from dsi_display_init_dsi() and dsi_display_uninit_dsi().

We need to make these two changes together to avoid breaking things
for DVI when fixing the DSI clock handling. And this all causes a
slight renumbering of the error path for dsi_display_init_dsi().

Suggested-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent bdc09563

drivers/gpu/drm/omapdrm/dss/dsi.c

+31 −29
Original line number Diff line number Diff line
@@ -1386,12 +1386,9 @@ static int dsi_pll_enable(struct dss_pll *pll) 
	 */

	dsi_enable_scp_clk(dsi);



	if (!dsi->vdds_dsi_enabled) {

	r = regulator_enable(dsi->vdds_dsi_reg);

	if (r)

		goto err0;

		dsi->vdds_dsi_enabled = true;

	}



	/* XXX PLL does not come out of reset without this... */

	dispc_pck_free_enable(dsi->dss->dispc, 1);
@@ -1416,36 +1413,25 @@ static int dsi_pll_enable(struct dss_pll *pll) 


	return 0;

err1:

	if (dsi->vdds_dsi_enabled) {

	regulator_disable(dsi->vdds_dsi_reg);

		dsi->vdds_dsi_enabled = false;

	}

err0:

	dsi_disable_scp_clk(dsi);

	dsi_runtime_put(dsi);

	return r;

}



static void dsi_pll_uninit(struct dsi_data *dsi, bool disconnect_lanes)

static void dsi_pll_disable(struct dss_pll *pll)

{

	struct dsi_data *dsi = container_of(pll, struct dsi_data, pll);



	dsi_pll_power(dsi, DSI_PLL_POWER_OFF);

	if (disconnect_lanes) {

		WARN_ON(!dsi->vdds_dsi_enabled);



	regulator_disable(dsi->vdds_dsi_reg);

		dsi->vdds_dsi_enabled = false;

	}



	dsi_disable_scp_clk(dsi);

	dsi_runtime_put(dsi);



	DSSDBG("PLL uninit done\n");

}



static void dsi_pll_disable(struct dss_pll *pll)

{

	struct dsi_data *dsi = container_of(pll, struct dsi_data, pll);



	dsi_pll_uninit(dsi, true);

	DSSDBG("PLL disable done\n");

}



static void dsi_dump_dsi_clocks(struct dsi_data *dsi, struct seq_file *s)
@@ -4195,11 +4181,11 @@ static int dsi_display_init_dsi(struct dsi_data *dsi) 


	r = dss_pll_enable(&dsi->pll);

	if (r)

		goto err0;

		return r;



	r = dsi_configure_dsi_clocks(dsi);

	if (r)

		goto err1;

		goto err0;



	dss_select_dsi_clk_source(dsi->dss, dsi->module_id,

				  dsi->module_id == 0 ?
@@ -4207,6 +4193,14 @@ static int dsi_display_init_dsi(struct dsi_data *dsi) 


	DSSDBG("PLL OK\n");



	if (!dsi->vdds_dsi_enabled) {

		r = regulator_enable(dsi->vdds_dsi_reg);

		if (r)

			goto err1;



		dsi->vdds_dsi_enabled = true;

	}



	r = dsi_cio_init(dsi);

	if (r)

		goto err2;
@@ -4235,10 +4229,13 @@ static int dsi_display_init_dsi(struct dsi_data *dsi) 
err3:

	dsi_cio_uninit(dsi);

err2:

	dss_select_dsi_clk_source(dsi->dss, dsi->module_id, DSS_CLK_SRC_FCK);

	regulator_disable(dsi->vdds_dsi_reg);

	dsi->vdds_dsi_enabled = false;

err1:

	dss_pll_disable(&dsi->pll);

	dss_select_dsi_clk_source(dsi->dss, dsi->module_id, DSS_CLK_SRC_FCK);

err0:

	dss_pll_disable(&dsi->pll);



	return r;

}
@@ -4257,7 +4254,12 @@ static void dsi_display_uninit_dsi(struct dsi_data *dsi, bool disconnect_lanes, 


	dss_select_dsi_clk_source(dsi->dss, dsi->module_id, DSS_CLK_SRC_FCK);

	dsi_cio_uninit(dsi);

	dsi_pll_uninit(dsi, disconnect_lanes);

	dss_pll_disable(&dsi->pll);



	if (disconnect_lanes) {

		regulator_disable(dsi->vdds_dsi_reg);

		dsi->vdds_dsi_enabled = false;

	}

}



static int dsi_display_enable(struct omap_dss_device *dssdev)