diff options
| author | Stefan Wahren <wahrenst@gmx.net> | 2024-12-02 01:16:31 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-12-04 16:30:05 +0100 |
| commit | 1cf1bd88f129f3bd647fead4dca270a5894274bb (patch) | |
| tree | 9b2ab0374713e95bf25cf7c0026fa7620eaccc02 | |
| parent | a8d3e4a734599c7d0f6735f8db8a812e503395dd (diff) | |
| download | lwn-1cf1bd88f129f3bd647fead4dca270a5894274bb.tar.gz lwn-1cf1bd88f129f3bd647fead4dca270a5894274bb.zip | |
usb: dwc2: Fix HCD port connection race
On Raspberry Pis without onboard USB hub frequent device reconnects
can trigger a interrupt storm after DWC2 entered host clock gating.
This is caused by a race between _dwc2_hcd_suspend() and the port
interrupt, which sets port_connect_status. The issue occurs if
port_connect_status is still 1, but there is no connection anymore:
usb 1-1: USB disconnect, device number 25
dwc2 3f980000.usb: _dwc2_hcd_suspend: port_connect_status: 1
dwc2 3f980000.usb: Entering host clock gating.
Disabling IRQ #66
irq 66: nobody cared (try booting with the "irqpoll" option)
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-gc1bb81b13202-dirty #322
Hardware name: BCM2835
Call trace:
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x50/0x64
dump_stack_lvl from __report_bad_irq+0x38/0xc0
__report_bad_irq from note_interrupt+0x2ac/0x2f4
note_interrupt from handle_irq_event+0x88/0x8c
handle_irq_event from handle_level_irq+0xb4/0x1ac
handle_level_irq from generic_handle_domain_irq+0x24/0x34
generic_handle_domain_irq from bcm2836_chained_handle_irq+0x24/0x28
bcm2836_chained_handle_irq from generic_handle_domain_irq+0x24/0x34
generic_handle_domain_irq from generic_handle_arch_irq+0x34/0x44
generic_handle_arch_irq from __irq_svc+0x88/0xb0
Exception stack(0xc1d01f20 to 0xc1d01f68)
1f20: 0004ef3c 00000001 00000000 00000000 c1d09780 c1f6bb5c c1d04e54 c1c60ca8
1f40: c1d04e94 00000000 00000000 c1d092a8 c1f6af20 c1d01f70 c1211b98 c1212f40
1f60: 60000013 ffffffff
__irq_svc from default_idle_call+0x1c/0xb0
default_idle_call from do_idle+0x21c/0x284
do_idle from cpu_startup_entry+0x28/0x2c
cpu_startup_entry from kernel_init+0x0/0x12c
handlers:
[<e3a25c00>] dwc2_handle_common_intr
[<58bf98a3>] usb_hcd_irq
Disabling IRQ #66
So avoid this by reading the connection status directly.
Fixes: 113f86d0c302 ("usb: dwc2: Update partial power down entering by system suspend")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20241202001631.75473-4-wahrenst@gmx.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/dwc2/hcd.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index fb4fbd8c43df..8c3941ecaaf5 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -4345,7 +4345,7 @@ static int _dwc2_hcd_suspend(struct usb_hcd *hcd) if (hsotg->bus_suspended) goto skip_power_saving; - if (hsotg->flags.b.port_connect_status == 0) + if (!(dwc2_read_hprt0(hsotg) & HPRT0_CONNSTS)) goto skip_power_saving; switch (hsotg->params.power_down) { |