From c14f8a4032efa73d9c4e155add47c19252b3bdf4 Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda Date: Mon, 27 Jun 2016 15:36:53 +0900 Subject: [PATCH] phy: rcar-gen3-usb2: fix mutex_lock calling in interrupt This patch fixes an issue that the extcon_set_cable_state_() is possible to cause "BUG: scheduling while atomic" because this driver calls extcon_set_cable_state_() in the interrupt handler and mutex_lock() is possible to be called by like the following call trace. So, this patch adds a workqueue function to resolve this issue. [ 9.706504] BUG: scheduling while atomic: systemd-journal/25893/0x00010303 [ 9.714569] Modules linked in: [ 9.717629] CPU: 0 PID: 25893 Comm: systemd-journal Not tainted 4.7.0-rc4+ #86 [ 9.724844] Hardware name: Renesas Salvator-X board based on r8a7795 (DT) [ 9.731624] Call trace: [ 9.734077] [] dump_backtrace+0x0/0x1a8 [ 9.739470] [] show_stack+0x14/0x20 [ 9.744520] [] dump_stack+0x94/0xb8 [ 9.749568] [] __schedule_bug+0x44/0x58 [ 9.754966] [] __schedule+0x4e4/0x598 [ 9.760185] [] schedule+0x3c/0xa8 [ 9.765057] [] schedule_preempt_disabled+0x20/0x38 [ 9.771408] [] mutex_optimistic_spin+0x18c/0x1d0 [ 9.777583] [] __mutex_lock_slowpath+0x38/0x140 [ 9.783669] [] mutex_lock+0x44/0x60 [ 9.788717] [] kobject_uevent_env+0x250/0x500 [ 9.794634] [] extcon_update_state+0x220/0x298 [ 9.800634] [] extcon_set_cable_state_+0x78/0x88 [ 9.806812] [] rcar_gen3_device_recognition+0x5c/0xe0 [ 9.813420] [] rcar_gen3_phy_usb2_irq+0x3c/0x48 [ 9.819509] [] handle_irq_event_percpu+0x94/0x140 [ 9.825769] [] handle_irq_event+0x48/0x78 [ 9.831334] [] handle_fasteoi_irq+0xb8/0x1b0 [ 9.837162] [] generic_handle_irq+0x24/0x38 [ 9.842900] [] __handle_domain_irq+0x5c/0xb8 [ 9.848727] [] gic_handle_irq+0x58/0xb0 Reported-by: Simon Horman Fixes: 2b38543c8db1 ("phy: rcar-gen3-usb2: add extcon support") Signed-off-by: Yoshihiro Shimoda Signed-off-by: Kishon Vijay Abraham I --- drivers/phy/phy-rcar-gen3-usb2.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/drivers/phy/phy-rcar-gen3-usb2.c b/drivers/phy/phy-rcar-gen3-usb2.c index 4be3f5dbbc9f..31156c9c4707 100644 --- a/drivers/phy/phy-rcar-gen3-usb2.c +++ b/drivers/phy/phy-rcar-gen3-usb2.c @@ -21,6 +21,7 @@ #include #include #include +#include /******* USB2.0 Host registers (original offset is +0x200) *******/ #define USB2_INT_ENABLE 0x000 @@ -81,9 +82,25 @@ struct rcar_gen3_chan { struct extcon_dev *extcon; struct phy *phy; struct regulator *vbus; + struct work_struct work; + bool extcon_host; bool has_otg; }; +static void rcar_gen3_phy_usb2_work(struct work_struct *work) +{ + struct rcar_gen3_chan *ch = container_of(work, struct rcar_gen3_chan, + work); + + if (ch->extcon_host) { + extcon_set_cable_state_(ch->extcon, EXTCON_USB_HOST, true); + extcon_set_cable_state_(ch->extcon, EXTCON_USB, false); + } else { + extcon_set_cable_state_(ch->extcon, EXTCON_USB_HOST, false); + extcon_set_cable_state_(ch->extcon, EXTCON_USB, true); + } +} + static void rcar_gen3_set_host_mode(struct rcar_gen3_chan *ch, int host) { void __iomem *usb2_base = ch->base; @@ -130,8 +147,8 @@ static void rcar_gen3_init_for_host(struct rcar_gen3_chan *ch) rcar_gen3_set_host_mode(ch, 1); rcar_gen3_enable_vbus_ctrl(ch, 1); - extcon_set_cable_state_(ch->extcon, EXTCON_USB_HOST, true); - extcon_set_cable_state_(ch->extcon, EXTCON_USB, false); + ch->extcon_host = true; + schedule_work(&ch->work); } static void rcar_gen3_init_for_peri(struct rcar_gen3_chan *ch) @@ -140,8 +157,8 @@ static void rcar_gen3_init_for_peri(struct rcar_gen3_chan *ch) rcar_gen3_set_host_mode(ch, 0); rcar_gen3_enable_vbus_ctrl(ch, 0); - extcon_set_cable_state_(ch->extcon, EXTCON_USB_HOST, false); - extcon_set_cable_state_(ch->extcon, EXTCON_USB, true); + ch->extcon_host = false; + schedule_work(&ch->work); } static bool rcar_gen3_check_id(struct rcar_gen3_chan *ch) @@ -301,6 +318,7 @@ static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev) if (irq >= 0) { int ret; + INIT_WORK(&channel->work, rcar_gen3_phy_usb2_work); irq = devm_request_irq(dev, irq, rcar_gen3_phy_usb2_irq, IRQF_SHARED, dev_name(dev), channel); if (irq < 0) -- 2.20.1