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Commit 4e90a6eb authored by chunhui dai's avatar chunhui dai Committed by CK Hu
Browse files

drm/mediatek: add refcount for DPI power on/off 



After the kernel 4.4, the DRM disable flow was changed, if DPI was
disableed before CRTC, it will cause warning message as following:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 1339 at ../../linux/linux-4.4.24-mtk/drivers/gpu/drm/drm_irq.c:1326 drm_wait_one_vblank+0x188/0x18c()
vblank wait timed out on crtc 0
Modules linked in: bridge mt8521p_ir_shim(O) i2c_eeprom(O) mtk_m4(O) fuse_ctrl(O) virtual_block(O) caamkeys(PO) chk(PO) amperctl(O) ledctl(O) apple_auth(PO) micctl(O) sensors(PO) lla(O) sdd(PO) ice40_fpga(O) psmon(O) event_queue(PO) utils(O) blackbox(O)
CPU: 0 PID: 1339 Comm: kworker/0:1 Tainted: P        W  O    4.4.24 #1
Hardware name: Mediatek Cortex-A7 (Device Tree)
Workqueue: events drm_mode_rmfb_work_fn
[<c001a710>] (unwind_backtrace) from [<c00151e4>] (show_stack+0x20/0x24)
[<c00151e4>] (show_stack) from [<c027961c>] (dump_stack+0x98/0xac)
[<c027961c>] (dump_stack) from [<c002ac54>] (warn_slowpath_common+0x94/0xc4)
[<c002ac54>] (warn_slowpath_common) from [<c002acc4>] (warn_slowpath_fmt+0x40/0x48)
[<c002acc4>] (warn_slowpath_fmt) from [<c03307ac>] (drm_wait_one_vblank+0x188/0x18c)
[<c03307ac>] (drm_wait_one_vblank) from [<c03307d8>] (drm_crtc_wait_one_vblank+0x28/0x2c)
[<c03307d8>] (drm_crtc_wait_one_vblank) from [<c034f48c>] (mtk_drm_crtc_disable+0x78/0x240)
[<c034f48c>] (mtk_drm_crtc_disable) from [<c03240d4>] (drm_atomic_helper_commit_modeset_disables+0x128/0x3b8)
[<c03240d4>] (drm_atomic_helper_commit_modeset_disables) from [<c0350a7c>] (mtk_atomic_complete+0x74/0xb4)
[<c0350a7c>] (mtk_atomic_complete) from [<c0350b24>] (mtk_atomic_commit+0x68/0x98)
[<c0350b24>] (mtk_atomic_commit) from [<c034ab48>] (drm_atomic_commit+0x54/0x74)
[<c034ab48>] (drm_atomic_commit) from [<c0325c4c>] (drm_atomic_helper_set_config+0x7c/0xa0)
[<c0325c4c>] (drm_atomic_helper_set_config) from [<c0338594>] (drm_mode_set_config_internal+0x68/0xe4)
[<c0338594>] (drm_mode_set_config_internal) from [<c033967c>] (drm_framebuffer_remove+0xe4/0x120)
[<c033967c>] (drm_framebuffer_remove) from [<c0339700>] (drm_mode_rmfb_work_fn+0x48/0x58)
[<c0339700>] (drm_mode_rmfb_work_fn) from [<c0043a38>] (process_one_work+0x154/0x50c)
[<c0043a38>] (process_one_work) from [<c0044074>] (worker_thread+0x284/0x568)
[<c0044074>] (worker_thread) from [<c0049dc4>] (kthread+0xec/0x104)
[<c0049dc4>] (kthread) from [<c0010678>] (ret_from_fork+0x14/0x3c)
---[ end trace 12ae5358e992abd5 ]---

so, we add refcount for DPI power on/off to protect the flow.

Signed-off-by: default avatarBibby Hsieh <bibby.hsieh@mediatek.com>
Signed-off-by: default avatarchunhui dai <chunhui.dai@mediatek.com>
Signed-off-by: default avatarCK Hu <ck.hu@mediatek.com>
parent 87c2ee74

drivers/gpu/drm/mediatek/mtk_dpi.c

+13 −30
Original line number Diff line number Diff line
@@ -76,8 +76,7 @@ struct mtk_dpi { 
	enum mtk_dpi_out_yc_map yc_map;

	enum mtk_dpi_out_bit_num bit_num;

	enum mtk_dpi_out_channel_swap channel_swap;

	bool power_sta;

	u8 power_ctl;

	int refcount;

};



static inline struct mtk_dpi *mtk_dpi_from_encoder(struct drm_encoder *e)
@@ -90,11 +89,6 @@ enum mtk_dpi_polarity { 
	MTK_DPI_POLARITY_FALLING,

};



enum mtk_dpi_power_ctl {

	DPI_POWER_START = BIT(0),

	DPI_POWER_ENABLE = BIT(1),

};



struct mtk_dpi_polarities {

	enum mtk_dpi_polarity de_pol;

	enum mtk_dpi_polarity ck_pol;
@@ -367,40 +361,30 @@ static void mtk_dpi_config_color_format(struct mtk_dpi *dpi, 
	}

}



static void mtk_dpi_power_off(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl)

static void mtk_dpi_power_off(struct mtk_dpi *dpi)

{

	dpi->power_ctl &= ~pctl;



	if ((dpi->power_ctl & DPI_POWER_START) ||

	    (dpi->power_ctl & DPI_POWER_ENABLE))

	if (WARN_ON(dpi->refcount == 0))

		return;



	if (!dpi->power_sta)

	if (--dpi->refcount != 0)

		return;



	mtk_dpi_disable(dpi);

	clk_disable_unprepare(dpi->pixel_clk);

	clk_disable_unprepare(dpi->engine_clk);

	dpi->power_sta = false;

}



static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl)

static int mtk_dpi_power_on(struct mtk_dpi *dpi)

{

	int ret;



	dpi->power_ctl |= pctl;



	if (!(dpi->power_ctl & DPI_POWER_START) &&

	    !(dpi->power_ctl & DPI_POWER_ENABLE))

		return 0;



	if (dpi->power_sta)

	if (++dpi->refcount != 1)

		return 0;



	ret = clk_prepare_enable(dpi->engine_clk);

	if (ret) {

		dev_err(dpi->dev, "Failed to enable engine clock: %d\n", ret);

		goto err_eng;

		goto err_refcount;

	}



	ret = clk_prepare_enable(dpi->pixel_clk);
@@ -410,13 +394,12 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl) 
	}



	mtk_dpi_enable(dpi);

	dpi->power_sta = true;

	return 0;



err_pixel:

	clk_disable_unprepare(dpi->engine_clk);

err_eng:

	dpi->power_ctl &= ~pctl;

err_refcount:

	dpi->refcount--;

	return ret;

}
@@ -552,14 +535,14 @@ static void mtk_dpi_encoder_disable(struct drm_encoder *encoder) 
{

	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);



	mtk_dpi_power_off(dpi, DPI_POWER_ENABLE);

	mtk_dpi_power_off(dpi);

}



static void mtk_dpi_encoder_enable(struct drm_encoder *encoder)

{

	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);



	mtk_dpi_power_on(dpi, DPI_POWER_ENABLE);

	mtk_dpi_power_on(dpi);

	mtk_dpi_set_display_mode(dpi, &dpi->mode);

}
@@ -582,14 +565,14 @@ static void mtk_dpi_start(struct mtk_ddp_comp *comp) 
{

	struct mtk_dpi *dpi = container_of(comp, struct mtk_dpi, ddp_comp);



	mtk_dpi_power_on(dpi, DPI_POWER_START);

	mtk_dpi_power_on(dpi);

}



static void mtk_dpi_stop(struct mtk_ddp_comp *comp)

{

	struct mtk_dpi *dpi = container_of(comp, struct mtk_dpi, ddp_comp);



	mtk_dpi_power_off(dpi, DPI_POWER_START);

	mtk_dpi_power_off(dpi);

}



static const struct mtk_ddp_comp_funcs mtk_dpi_funcs = {