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TESTING: V6.12 dwc hcd fixes #6496

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Do not merge - just to create a test build.

This helps to reproduce issue faster ...

Signed-off-by: Stefan Wahren <[email protected]>
The Raspberry Pi can suffer on interrupt storms on HCD resume. The dwc2
driver sometimes misses to enable HCD_FLAG_HW_ACCESSIBLE before re-enabling
the interrupts. This causes a situation where both handler ignore a incoming
port interrupt and force the upper layers to disable the dwc2 interrupt
line. This leaves the USB interface in a unusable state:

irq 66: nobody cared (try booting with the "irqpoll" option)
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W          6.10.0-rc3
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(0xc1b01f20 to 0xc1b01f68)
1f20: 0005c0d4 00000001 00000000 00000000 c1b09780 c1d6b32c c1b04e54 c1a5eae8
1f40: c1b04e90 00000000 00000000 00000000 c1d6a8a0 c1b01f70 c11d2da8 c11d4160
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:
[<f539e0f4>] dwc2_handle_common_intr
[<75cd278b>] usb_hcd_irq
Disabling IRQ raspberrypi#66

So enable the HCD_FLAG_HW_ACCESSIBLE flag in case there is a port
connection.

Fixes: c74c26f ("usb: dwc2: Fix partial power down exiting by system resume")
Link: https://lore.kernel.org/linux-usb/[email protected]/T/
Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Stefan Wahren <[email protected]>
On Rasperry Pis without onboard USB hub the power cycle during
power connect init only disable the port but never enabled it again:

  usb usb1-port1: attempt power cycle

The port relevant part in dwc2_hcd_hub_control() is skipped in case
port_connect_status = 0 under the assumption the core is or will be soon
in device mode. But this assumption is wrong, because after ClearPortFeature
USB_PORT_FEAT_POWER the port_connect_status will also be 0 and
SetPortFeature (incl. USB_PORT_FEAT_POWER) will be a no-op.

Fix the behavior of dwc2_hcd_hub_control() by replacing the
port_connect_status check with dwc2_is_device_mode().

Link: raspberrypi#6247
Fixes: 7359d48 ("staging: HCD files for the DWC2 driver")
Signed-off-by: Stefan Wahren <[email protected]>
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 raspberrypi#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 raspberrypi#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 raspberrypi#66

So avoid this by reading the connection status directly.

Fixes: 113f86d ("usb: dwc2: Update partial power down entering by system suspend")
Signed-off-by: Stefan Wahren <[email protected]>
@pelwell pelwell marked this pull request as draft November 26, 2024 20:18
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