6.6-stable review patch. If anyone has any objections, please let me know.
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From: Stefan Wahren wahrenst@gmx.net
commit 1cf1bd88f129f3bd647fead4dca270a5894274bb upstream.
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 --- drivers/usb/dwc2/hcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -4345,7 +4345,7 @@ static int _dwc2_hcd_suspend(struct usb_ 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) {