Hello,
I think I found the solution.
The problem is that new USB driver for Raspberry Pi uses FIQ in a manner that leads to lockups on SMP systems, while booting of the older non-FIQ driver was broken.
The following patch fixes an error and allows to boot the non-FIQ driver:
---
drivers/usb/host/dwc_otg/dwc_otg_hcd.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
index 68534d4..6a006c5 100644
--- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
+++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
@@ -1414,8 +1414,12 @@ static void assign_and_init_hc(dwc_otg_hcd_t * hcd, dwc_otg_qh_t * qh)
dwc_otg_hc_init(hcd->core_if, hc);
local_irq_save(flags);
- local_fiq_disable();
- fiq_fsm_spin_lock(&hcd->fiq_state->lock);
+
+ if (fiq_enable) {
+ local_fiq_disable();
+ fiq_fsm_spin_lock(&hcd->fiq_state->lock);
+ }
+
/* Enable the top level host channel interrupt. */
intr_enable = (1 << hc->hc_num);
DWC_MODIFY_REG32(&hcd->core_if->host_if->host_global_regs->haintmsk, 0, intr_enable);
@@ -1423,8 +1427,12 @@ static void assign_and_init_hc(dwc_otg_hcd_t * hcd, dwc_otg_qh_t * qh)
/* Make sure host channel interrupts are enabled. */
gintmsk.b.hcintr = 1;
DWC_MODIFY_REG32(&hcd->core_if->core_global_regs->gintmsk, 0, gintmsk.d32);
- fiq_fsm_spin_unlock(&hcd->fiq_state->lock);
- local_fiq_enable();
+
+ if (fiq_enable) {
+ fiq_fsm_spin_unlock(&hcd->fiq_state->lock);
+ local_fiq_enable();
+ }
+
local_irq_restore(flags);
hc->qh = qh;
}
--
To boot the with the non-FIQ driver add this to the /boot/cmdline.txt:
dwc_otg.fiq_enable=0 dwc_otg.fiq_fsm_enable=0 dwc_otg.nak_holdoff=0
Best regards,
Mikhail Avkhimenia
09.03.2015, 17:13, "Sebastian Andrzej Siewior" <bigeasy@xxxxxxxxxxxxx>:
> * Julien Ciesla | 2015-03-09 01:55:49 [+0000]:
>> Same issue on linux raspberrypi 3.18.9 with patch rt4.
>
> Then disable USB completely.
>
> Sebastian
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
