| Message ID | 20180921032822.30771-2-bibby.hsieh@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/mediatek: support hdmi output for mt2701 and mt7623 | expand |
Hi, Bibby: On Fri, 2018-09-21 at 11:28 +0800, Bibby Hsieh wrote: > From: chunhui dai <chunhui.dai@mediatek.com> > > 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: Bibby Hsieh <bibby.hsieh@mediatek.com> > Signed-off-by: chunhui dai <chunhui.dai@mediatek.com> > --- > drivers/gpu/drm/mediatek/mtk_dpi.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c > index 6c0ea39d5739..d9373e67d328 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c > @@ -77,6 +77,7 @@ struct mtk_dpi { > enum mtk_dpi_out_bit_num bit_num; > enum mtk_dpi_out_channel_swap channel_swap; > bool power_sta; > + int refcount; > u8 power_ctl; > }; > > @@ -369,6 +370,12 @@ 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) > { > + if (WARN_ON(dpi->refcount == 0)) > + return; > + > + if (--dpi->refcount != 0) > + return; > + > dpi->power_ctl &= ~pctl; > > if ((dpi->power_ctl & DPI_POWER_START) || > @@ -388,14 +395,17 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl) > { > int ret; > > + if (++dpi->refcount != 1) > + return 0; > + > dpi->power_ctl |= pctl; > > if (!(dpi->power_ctl & DPI_POWER_START) && > !(dpi->power_ctl & DPI_POWER_ENABLE)) > - return 0; > + goto err_refcount; > > if (dpi->power_sta) > - return 0; > + goto err_refcount; I think dpi->power_ctl and dpi->power_sta is something like reference count. mtk_dpi_start() and mtk_dpi_stop() is called by crtc. If the error message happen without this patch, I think there is a bug in dpi->power_ctl and dpi->power_sta. I think you should fix the bug of dpi->power_ctl and dpi->power_sta, or just replace it with your reference count mechanism. Regards, CK > > ret = clk_prepare_enable(dpi->engine_clk); > if (ret) { > @@ -417,6 +427,8 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl) > clk_disable_unprepare(dpi->engine_clk); > err_eng: > dpi->power_ctl &= ~pctl; > +err_refcount: > + dpi->refcount--; > return ret; > } >
diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c index 6c0ea39d5739..d9373e67d328 100644 --- a/drivers/gpu/drm/mediatek/mtk_dpi.c +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c @@ -77,6 +77,7 @@ struct mtk_dpi { enum mtk_dpi_out_bit_num bit_num; enum mtk_dpi_out_channel_swap channel_swap; bool power_sta; + int refcount; u8 power_ctl; }; @@ -369,6 +370,12 @@ 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) { + if (WARN_ON(dpi->refcount == 0)) + return; + + if (--dpi->refcount != 0) + return; + dpi->power_ctl &= ~pctl; if ((dpi->power_ctl & DPI_POWER_START) || @@ -388,14 +395,17 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl) { int ret; + if (++dpi->refcount != 1) + return 0; + dpi->power_ctl |= pctl; if (!(dpi->power_ctl & DPI_POWER_START) && !(dpi->power_ctl & DPI_POWER_ENABLE)) - return 0; + goto err_refcount; if (dpi->power_sta) - return 0; + goto err_refcount; ret = clk_prepare_enable(dpi->engine_clk); if (ret) { @@ -417,6 +427,8 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl) clk_disable_unprepare(dpi->engine_clk); err_eng: dpi->power_ctl &= ~pctl; +err_refcount: + dpi->refcount--; return ret; }