[PATCH V2 13/16] usb: dwc2: Skip clock gating on Broadcom SoCs

[Stefan Wahren]

On resume of the Raspberry Pi the dwc2 driver fails 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 #66

Disabling clock gating workaround this issue.

Fixes: 0112b7ce68ea ("usb: dwc2: Update dwc2_handle_usb_suspend_intr function.")
Link: https://lore.kernel.org/linux-usb/3fd0c2fb-4752-45b3-94eb-42352703e1fd@gmx.net/T/
Link: https://lore.kernel.org/all/5e8cbce0-3260-2971-484f-fc73a3b2bd28@synopsys.com/
Signed-off-by: Stefan Wahren <wahrenst at gmx.net>
Acked-by: Minas Harutyunyan <hminas at synopsys.com>
---
 drivers/usb/dwc2/params.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c
index 4d73fae80b12..68226defdc60 100644
--- a/drivers/usb/dwc2/params.c
+++ b/drivers/usb/dwc2/params.c
@@ -23,6 +23,7 @@ static void dwc2_set_bcm_params(struct dwc2_hsotg *hsotg)
 	p->max_transfer_size = 65535;
 	p->max_packet_count = 511;
 	p->ahbcfg = 0x10;
+	p->no_clock_gating = true;
 }

 static void dwc2_set_his_params(struct dwc2_hsotg *hsotg)
--
2.34.1