| Message ID | 20230725073234.55892-7-angelogioacchino.delregno@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | MediaTek DisplayPort: support eDP and aux-bus | expand |
Hi, Angelo: On Tue, 2023-07-25 at 09:32 +0200, AngeloGioacchino Del Regno wrote: > It is useless and error-prone to enable the DisplayPort event > interrupt > before finishing to probe and install the driver, as the DP training > cannot happen before the entire pipeline is correctly set up, as the > interrupt handler also requires the full hardware to be initialized > by > mtk_dp_bridge_attach(). > > Anyway, depending in which state the controller is left from the > bootloader, this may cause an interrupt storm and consequently hang > the kernel during boot, so, avoid enabling the interrupt until we > reach a clean state by adding the IRQ_NOAUTOEN flag before requesting > it at probe time and manage the enablement of the ISR in the > .attach() > and .detach() handlers for the DP bridge. Reviewed-by: CK Hu <ck.hu@mediatek.com> > > Signed-off-by: AngeloGioacchino Del Regno < > angelogioacchino.delregno@collabora.com> > Tested-by: Chen-Yu Tsai <wenst@chromium.org> > Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com> > --- > drivers/gpu/drm/mediatek/mtk_dp.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c > b/drivers/gpu/drm/mediatek/mtk_dp.c > index e8d3bf310608..83e55f8dc84a 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dp.c > +++ b/drivers/gpu/drm/mediatek/mtk_dp.c > @@ -100,6 +100,7 @@ struct mtk_dp_efuse_fmt { > struct mtk_dp { > bool enabled; > bool need_debounce; > + int irq; > u8 max_lanes; > u8 max_linkrate; > u8 rx_cap[DP_RECEIVER_CAP_SIZE]; > @@ -2141,6 +2142,8 @@ static int mtk_dp_bridge_attach(struct > drm_bridge *bridge, > > mtk_dp->drm_dev = bridge->dev; > > + irq_clear_status_flags(mtk_dp->irq, IRQ_NOAUTOEN); > + enable_irq(mtk_dp->irq); > mtk_dp_hwirq_enable(mtk_dp, true); > > return 0; > @@ -2157,6 +2160,7 @@ static void mtk_dp_bridge_detach(struct > drm_bridge *bridge) > struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge); > > mtk_dp_hwirq_enable(mtk_dp, false); > + disable_irq(mtk_dp->irq); > mtk_dp->drm_dev = NULL; > mtk_dp_poweroff(mtk_dp); > drm_dp_aux_unregister(&mtk_dp->aux); > @@ -2475,7 +2479,7 @@ static int mtk_dp_probe(struct platform_device > *pdev) > { > struct mtk_dp *mtk_dp; > struct device *dev = &pdev->dev; > - int ret, irq_num; > + int ret; > > mtk_dp = devm_kzalloc(dev, sizeof(*mtk_dp), GFP_KERNEL); > if (!mtk_dp) > @@ -2484,9 +2488,9 @@ static int mtk_dp_probe(struct platform_device > *pdev) > mtk_dp->dev = dev; > mtk_dp->data = (struct mtk_dp_data > *)of_device_get_match_data(dev); > > - irq_num = platform_get_irq(pdev, 0); > - if (irq_num < 0) > - return dev_err_probe(dev, irq_num, > + mtk_dp->irq = platform_get_irq(pdev, 0); > + if (mtk_dp->irq < 0) > + return dev_err_probe(dev, mtk_dp->irq, > "failed to request dp irq > resource\n"); > > mtk_dp->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, > 1, 0); > @@ -2507,7 +2511,8 @@ static int mtk_dp_probe(struct platform_device > *pdev) > > spin_lock_init(&mtk_dp->irq_thread_lock); > > - ret = devm_request_threaded_irq(dev, irq_num, mtk_dp_hpd_event, > + irq_set_status_flags(mtk_dp->irq, IRQ_NOAUTOEN); > + ret = devm_request_threaded_irq(dev, mtk_dp->irq, > mtk_dp_hpd_event, > mtk_dp_hpd_event_thread, > IRQ_TYPE_LEVEL_HIGH, > dev_name(dev), > mtk_dp);
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c index e8d3bf310608..83e55f8dc84a 100644 --- a/drivers/gpu/drm/mediatek/mtk_dp.c +++ b/drivers/gpu/drm/mediatek/mtk_dp.c @@ -100,6 +100,7 @@ struct mtk_dp_efuse_fmt { struct mtk_dp { bool enabled; bool need_debounce; + int irq; u8 max_lanes; u8 max_linkrate; u8 rx_cap[DP_RECEIVER_CAP_SIZE]; @@ -2141,6 +2142,8 @@ static int mtk_dp_bridge_attach(struct drm_bridge *bridge, mtk_dp->drm_dev = bridge->dev; + irq_clear_status_flags(mtk_dp->irq, IRQ_NOAUTOEN); + enable_irq(mtk_dp->irq); mtk_dp_hwirq_enable(mtk_dp, true); return 0; @@ -2157,6 +2160,7 @@ static void mtk_dp_bridge_detach(struct drm_bridge *bridge) struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge); mtk_dp_hwirq_enable(mtk_dp, false); + disable_irq(mtk_dp->irq); mtk_dp->drm_dev = NULL; mtk_dp_poweroff(mtk_dp); drm_dp_aux_unregister(&mtk_dp->aux); @@ -2475,7 +2479,7 @@ static int mtk_dp_probe(struct platform_device *pdev) { struct mtk_dp *mtk_dp; struct device *dev = &pdev->dev; - int ret, irq_num; + int ret; mtk_dp = devm_kzalloc(dev, sizeof(*mtk_dp), GFP_KERNEL); if (!mtk_dp) @@ -2484,9 +2488,9 @@ static int mtk_dp_probe(struct platform_device *pdev) mtk_dp->dev = dev; mtk_dp->data = (struct mtk_dp_data *)of_device_get_match_data(dev); - irq_num = platform_get_irq(pdev, 0); - if (irq_num < 0) - return dev_err_probe(dev, irq_num, + mtk_dp->irq = platform_get_irq(pdev, 0); + if (mtk_dp->irq < 0) + return dev_err_probe(dev, mtk_dp->irq, "failed to request dp irq resource\n"); mtk_dp->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0); @@ -2507,7 +2511,8 @@ static int mtk_dp_probe(struct platform_device *pdev) spin_lock_init(&mtk_dp->irq_thread_lock); - ret = devm_request_threaded_irq(dev, irq_num, mtk_dp_hpd_event, + irq_set_status_flags(mtk_dp->irq, IRQ_NOAUTOEN); + ret = devm_request_threaded_irq(dev, mtk_dp->irq, mtk_dp_hpd_event, mtk_dp_hpd_event_thread, IRQ_TYPE_LEVEL_HIGH, dev_name(dev), mtk_dp);