From: chunhui dai Date: Wed, 3 Oct 2018 03:41:41 +0000 (+0800) Subject: drm/mediatek: add refcount for DPI power on/off X-Git-Tag: v5.15~7648^2~8^2~10 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4e90a6eb769a2041a81efb3c288a087790ae885d;p=platform%2Fkernel%2Flinux-starfive.git 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 [] (unwind_backtrace) from [] (show_stack+0x20/0x24) [] (show_stack) from [] (dump_stack+0x98/0xac) [] (dump_stack) from [] (warn_slowpath_common+0x94/0xc4) [] (warn_slowpath_common) from [] (warn_slowpath_fmt+0x40/0x48) [] (warn_slowpath_fmt) from [] (drm_wait_one_vblank+0x188/0x18c) [] (drm_wait_one_vblank) from [] (drm_crtc_wait_one_vblank+0x28/0x2c) [] (drm_crtc_wait_one_vblank) from [] (mtk_drm_crtc_disable+0x78/0x240) [] (mtk_drm_crtc_disable) from [] (drm_atomic_helper_commit_modeset_disables+0x128/0x3b8) [] (drm_atomic_helper_commit_modeset_disables) from [] (mtk_atomic_complete+0x74/0xb4) [] (mtk_atomic_complete) from [] (mtk_atomic_commit+0x68/0x98) [] (mtk_atomic_commit) from [] (drm_atomic_commit+0x54/0x74) [] (drm_atomic_commit) from [] (drm_atomic_helper_set_config+0x7c/0xa0) [] (drm_atomic_helper_set_config) from [] (drm_mode_set_config_internal+0x68/0xe4) [] (drm_mode_set_config_internal) from [] (drm_framebuffer_remove+0xe4/0x120) [] (drm_framebuffer_remove) from [] (drm_mode_rmfb_work_fn+0x48/0x58) [] (drm_mode_rmfb_work_fn) from [] (process_one_work+0x154/0x50c) [] (process_one_work) from [] (worker_thread+0x284/0x568) [] (worker_thread) from [] (kthread+0xec/0x104) [] (kthread) from [] (ret_from_fork+0x14/0x3c) ---[ end trace 12ae5358e992abd5 ]--- so, we add refcount for DPI power on/off to protect the flow. Signed-off-by: Bibby Hsieh Signed-off-by: chunhui dai Signed-off-by: CK Hu --- diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c index 6c0ea39..5ede1dd 100644 --- a/drivers/gpu/drm/mediatek/mtk_dpi.c +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c @@ -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 = {