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On 10/07/2015 05:48 PM, Russell King -
ARM Linux wrote:
On Wed, Oct 07, 2015 at 12:05:37PM +0800, Yakir Yang wrote:On 08/09/2015 12:04 AM, Russell King wrote:The dw_hdmi enable/disable handling is particularly weak in several regards: * The hotplug interrupt could call hdmi_poweron() or hdmi_poweroff() while DRM is setting a mode, which could race with a mode being set. * Hotplug will always re-enable the phy whenever it detects an active hotplug signal, even if DRM has disabled the output. Resolve all of these by introducing a mutex to prevent races, and a state-tracking bool so we know whether DRM wishes the output to be enabled. We choose to use our own mutex rather than ->struct_mutex so that we can still process interrupts in a timely fashion. Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> --- drivers/gpu/drm/bridge/dw_hdmi.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c index 7b8a4e942a71..0ee188930d26 100644 --- a/drivers/gpu/drm/bridge/dw_hdmi.c +++ b/drivers/gpu/drm/bridge/dw_hdmi.c @@ -125,6 +125,9 @@ struct dw_hdmi { bool sink_is_hdmi; bool sink_has_audio; + struct mutex mutex; /* for state below and previous_mode */ + bool disabled; /* DRM has disabled our bridge */ + spinlock_t audio_lock; struct mutex audio_mutex; unsigned int sample_rate; @@ -1389,8 +1392,12 @@ static void dw_hdmi_bridge_mode_set(struct drm_bridge *bridge, { struct dw_hdmi *hdmi = bridge->driver_private; + mutex_lock(&hdmi->mutex); + /* Store the display mode for plugin/DKMS poweron events */ memcpy(&hdmi->previous_mode, mode, sizeof(hdmi->previous_mode)); + + mutex_unlock(&hdmi->mutex); } static bool dw_hdmi_bridge_mode_fixup(struct drm_bridge *bridge, @@ -1404,14 +1411,20 @@ static void dw_hdmi_bridge_disable(struct drm_bridge *bridge) { struct dw_hdmi *hdmi = bridge->driver_private; + mutex_lock(&hdmi->mutex); + hdmi->disabled = true; dw_hdmi_poweroff(hdmi); + mutex_unlock(&hdmi->mutex); } static void dw_hdmi_bridge_enable(struct drm_bridge *bridge) { struct dw_hdmi *hdmi = bridge->driver_private; + mutex_lock(&hdmi->mutex); dw_hdmi_poweron(hdmi); + hdmi->disabled = false; + mutex_unlock(&hdmi->mutex); } static void dw_hdmi_bridge_nop(struct drm_bridge *bridge) @@ -1534,20 +1547,20 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id) phy_int_pol = hdmi_readb(hdmi, HDMI_PHY_POL0); if (intr_stat & HDMI_IH_PHY_STAT0_HPD) { + hdmi_modb(hdmi, ~phy_int_pol, HDMI_PHY_HPD, HDMI_PHY_POL0); + mutex_lock(&hdmi->mutex); if (phy_int_pol & HDMI_PHY_HPD) { dev_dbg(hdmi->dev, "EVENT=plugin\n"); - hdmi_modb(hdmi, 0, HDMI_PHY_HPD, HDMI_PHY_POL0); - - dw_hdmi_poweron(hdmi); + if (!hdmi->disabled) + dw_hdmi_poweron(hdmi); } else { dev_dbg(hdmi->dev, "EVENT=plugout\n"); - hdmi_modb(hdmi, HDMI_PHY_HPD, HDMI_PHY_HPD, - HDMI_PHY_POL0); - - dw_hdmi_poweroff(hdmi); + if (!hdmi->disabled) + dw_hdmi_poweroff(hdmi);Just like my reply on 08/12, I thought this could be removed, so poweron/poweroff would only be called with bridge->enable/ bridge->disable, them maybe no need mutex here.The bridge enable/disable methods do not get called on hotplug changes. [ 1.363011] dwhdmi-imx 120000.hdmi: Detected HDMI controller 0x13:0xa:0xa0:0xc1 [ 1.371341] dwhdmi-imx 120000.hdmi: dw_hdmi_irq(I:RX----,HPD P:RX3210,HPD S:RX----,HPD) [ 1.381345] imx-drm display-subsystem: bound 120000.hdmi (ops dw_hdmi_imx_ops) [ 1.448691] dwhdmi-imx 120000.hdmi: dw_hdmi_bridge_disable() [ 1.450963] dwhdmi-imx 120000.hdmi: dw_hdmi_bridge_enable() and then unplugging and re-plugging the HDMI cable: [ 68.307505] dwhdmi-imx 120000.hdmi: dw_hdmi_irq(I:RX----,HPD P:RX3210,--- S:RX----,---) [ 73.813970] dwhdmi-imx 120000.hdmi: dw_hdmi_irq(I:RX----,HPD P:RX3210,HPD S:RX----,HPD) As you can see, during the period of disconnection for five seconds, dw_hdmi_bridge_disable() was not called. So, without the code above, we'd be needlessly wasting power with the bridge enabled, trying to drive a disconnected display. Strangely, I do see bridge enable/disable in my side, past the log and dump_stack bellow. And I guess your HDMI maybe not really hot pluged, could you confirm that the "status" of HDMI display card have been changed between "connected" and "disconnected". Do see bridge_disable when I unpluging the HDMI cable [ 16.358717] dwhdmi-rockchip ff980000.hdmi: EVENT=plugout [ 20.613221] [<c010e030>] (unwind_backtrace) from [<c010a4e0>] (show_stack+0x20/0x24) [ 20.631561] [<c010a4e0>] (show_stack) from [<c0896828>] (dump_stack+0x70/0x8c) [ 20.649337] [<c0896828>] (dump_stack) from [<c0414038>] (dw_hdmi_bridge_disable+0x1c/0x88) [ 20.668178] [<c0414038>] (dw_hdmi_bridge_disable) from [<c03e3888>] (drm_encoder_disable+0x34/0x78) [ 20.687857] [<c03e3888>] (drm_encoder_disable) from [<c03e3b1c>] (__drm_helper_disable_unused_functions+0x68/0xe4) [ 20.708975] [<c03e3b1c>] (__drm_helper_disable_unused_functions) from [<c03e4320>] (drm_crtc_helper_set_config+0x128/0x85c) [ 20.731180] [<c03e4320>] (drm_crtc_helper_set_config) from [<c03f5e3c>] (drm_mode_set_config_internal+0x58/0xdc) [ 20.752507] [<c03f5e3c>] (drm_mode_set_config_internal) from [<c0405ed0>] (commit_crtc_state+0x124/0x1ec) [ 20.773342] [<c0405ed0>] (commit_crtc_state) from [<c04055d4>] (atomic_commit.isra.3+0x5c/0xc8) [ 20.793397] [<c04055d4>] (atomic_commit.isra.3) from [<c040565c>] (drm_atomic_commit+0x1c/0x20) [ 20.813467] [<c040565c>] (drm_atomic_commit) from [<c03fa480>] (drm_mode_setcrtc+0x324/0x3e4) [ 20.833379] [<c03fa480>] (drm_mode_setcrtc) from [<c03eb320>] (drm_ioctl+0x304/0x478) [ 20.852557] [<c03eb320>] (drm_ioctl) from [<c021f024>] (do_vfs_ioctl+0x494/0x5a8) [ 20.871377] [<c021f024>] (do_vfs_ioctl) from [<c021f194>] (SyS_ioctl+0x5c/0x84) [ 20.890038] [<c021f194>] (SyS_ioctl) from [<c010646c>] (__sys_trace_return+0x0/0x14) [ 16.890157] ------- YAKIR: dw_hdmi_bridge_disable:1656 [ 16.897907] ------- YAKIR: dw_hdmi_poweroff:1631 Also see bridge have been disabled once before try to bridge_enable when I try re-plugging the HDMI cable [ 20.494292] dwhdmi-rockchip ff980000.hdmi: EVENT=plugin [ 12.599389] [<c010e030>] (unwind_backtrace) from [<c010a4e0>] (show_stack+0x20/0x24) [ 12.612238] [<c010a4e0>] (show_stack) from [<c0896828>] (dump_stack+0x70/0x8c) [ 12.624609] [<c0896828>] (dump_stack) from [<c0414038>] (dw_hdmi_bridge_disable+0x1c/0x88) [ 12.638055] [<c0414038>] (dw_hdmi_bridge_disable) from [<c03e3dd4>] (drm_crtc_helper_set_mode+0x20c/0x4e0) [ 12.652878] [<c03e3dd4>] (drm_crtc_helper_set_mode) from [<c03e47ec>] (drm_crtc_helper_set_config+0x5f4/0x85c) [ 12.668019] [<c03e47ec>] (drm_crtc_helper_set_config) from [<c03f5e3c>] (drm_mode_set_config_internal+0x58/0xdc) [ 12.683442] [<c03f5e3c>] (drm_mode_set_config_internal) from [<c0405ed0>] (commit_crtc_state+0x124/0x1ec) [ 12.698287] [<c0405ed0>] (commit_crtc_state) from [<c04055d4>] (atomic_commit.isra.3+0x5c/0xc8) [ 12.712295] [<c04055d4>] (atomic_commit.isra.3) from [<c040565c>] (drm_atomic_commit+0x1c/0x20) [ 12.726258] [<c040565c>] (drm_atomic_commit) from [<c03fa480>] (drm_mode_setcrtc+0x324/0x3e4) [ 12.740226] [<c03fa480>] (drm_mode_setcrtc) from [<c03eb320>] (drm_ioctl+0x304/0x478) [ 12.753651] [<c03eb320>] (drm_ioctl) from [<c021f024>] (do_vfs_ioctl+0x494/0x5a8) [ 12.766794] [<c021f024>] (do_vfs_ioctl) from [<c021f194>] (SyS_ioctl+0x5c/0x84) [ 12.779861] [<c021f194>] (SyS_ioctl) from [<c010646c>] (__sys_trace_return+0x0/0x14) [ 21.059320] ------- YAKIR: dw_hdmi_bridge_disable:1656 [ 21.068272] ------- YAKIR: dw_hdmi_poweroff:1631 [ 21.076714] rockchip-vop ff930000.vop: start latency exceeded, new value 9333 ns [ 21.088037] rockchip-vop ff930000.vop: Attached to iommu domain [ 12.871336] [<c010e030>] (unwind_backtrace) from [<c010a4e0>] (show_stack+0x20/0x24) [ 12.882067] [<c010a4e0>] (show_stack) from [<c0896828>] (dump_stack+0x70/0x8c) [ 12.892311] [<c0896828>] (dump_stack) from [<c0414134>] (dw_hdmi_bridge_enable+0x3c/0xf28) [ 12.903569] [<c0414134>] (dw_hdmi_bridge_enable) from [<c03e3ff4>] (drm_crtc_helper_set_mode+0x42c/0x4e0) [ 12.916226] [<c03e3ff4>] (drm_crtc_helper_set_mode) from [<c03e47ec>] (drm_crtc_helper_set_config+0x5f4/0x85c) [ 12.929450] [<c03e47ec>] (drm_crtc_helper_set_config) from [<c03f5e3c>] (drm_mode_set_config_internal+0x58/0xdc) [ 12.942883] [<c03f5e3c>] (drm_mode_set_config_internal) from [<c0405ed0>] (commit_crtc_state+0x124/0x1ec) [ 12.955784] [<c0405ed0>] (commit_crtc_state) from [<c04055d4>] (atomic_commit.isra.3+0x5c/0xc8) [ 12.967753] [<c04055d4>] (atomic_commit.isra.3) from [<c040565c>] (drm_atomic_commit+0x1c/0x20) [ 12.979705] [<c040565c>] (drm_atomic_commit) from [<c03fa480>] (drm_mode_setcrtc+0x324/0x3e4) [ 12.991568] [<c03fa480>] (drm_mode_setcrtc) from [<c03eb320>] (drm_ioctl+0x304/0x478) [ 13.002817] [<c03eb320>] (drm_ioctl) from [<c021f024>] (do_vfs_ioctl+0x494/0x5a8) [ 13.013766] [<c021f024>] (do_vfs_ioctl) from [<c021f194>] (SyS_ioctl+0x5c/0x84) [ 13.024655] [<c021f194>] (SyS_ioctl) from [<c010646c>] (__sys_trace_return+0x0/0x14) [ 21.114556] ------- YAKIR: dw_hdmi_bridge_enable:1664 [ 21.122889] ------- YAKIR: dw_hdmi_poweron:1625 - Yakir |
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