From 73926db33b277c4c371edbc9fe9093adc9b2803b Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Fri, 14 Feb 2014 20:49:46 +0100 Subject: [PATCH] usb: musb: do not sleep in atomic context musb_port_reset() is called from musb_hub_control() which in turn holds a spinlock, so musb_port_reset() is not allowed to call msleep(). With the asynchronous work helpers in place, this is fortunately easy to fix by rescheduling the reset deassertion function to after the time when the wait period is finished. Note, however, that the MUSB_POWER_RESUME bit is only set on AM33xx processors under rare conditions such as when to another driver reporting an error during suspend. Hence, this didn't hit me yet in normal operation. Signed-off-by: Daniel Mack Signed-off-by: Greg Kroah-Hartman --- drivers/usb/musb/musb_core.c | 2 ++ drivers/usb/musb/musb_virthub.c | 20 +++++++++++++++----- 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c index fc192ad9cc6..1a377cac4d4 100644 --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -477,6 +477,8 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb, musb->port1_status |= (USB_PORT_STAT_C_SUSPEND << 16) | MUSB_PORT_STAT_RESUME; + musb->rh_timer = jiffies + + msecs_to_jiffies(20); schedule_delayed_work( &musb->finish_resume_work, 20); diff --git a/drivers/usb/musb/musb_virthub.c b/drivers/usb/musb/musb_virthub.c index eb634433ef0..32f49e1efa9 100644 --- a/drivers/usb/musb/musb_virthub.c +++ b/drivers/usb/musb/musb_virthub.c @@ -158,7 +158,6 @@ void musb_port_reset(struct musb *musb, bool do_reset) */ power = musb_readb(mbase, MUSB_POWER); if (do_reset) { - /* * If RESUME is set, we must make sure it stays minimum 20 ms. * Then we must clear RESUME and wait a bit to let musb start @@ -167,11 +166,22 @@ void musb_port_reset(struct musb *musb, bool do_reset) * detected". */ if (power & MUSB_POWER_RESUME) { - while (time_before(jiffies, musb->rh_timer)) - msleep(1); + long remain = (unsigned long) musb->rh_timer - jiffies; + + if (musb->rh_timer > 0 && remain > 0) { + /* take into account the minimum delay after resume */ + schedule_delayed_work( + &musb->deassert_reset_work, + jiffies_to_msecs(remain)); + return; + } + musb_writeb(mbase, MUSB_POWER, - power & ~MUSB_POWER_RESUME); - msleep(1); + power & ~MUSB_POWER_RESUME); + + /* Give the core 1 ms to clear MUSB_POWER_RESUME */ + schedule_delayed_work(&musb->deassert_reset_work, 1); + return; } power &= 0xf0; -- 2.41.0