bdk: usb: fix a race condition in USB2 stack

When RAM is slow (no training), it's possible to have the stack failing to negotiate configuration successfully.

The race condition is caused by not flushing cache before sending a configuration packet reply.
Although, cache is write-through, this needs to happen.
This commit is contained in:
CTCaer 2022-06-14 18:41:33 +03:00
parent 3fa01a1975
commit 605f270f98

View file

@ -785,13 +785,13 @@ static int _usbd_ep_operation(usb_ep_t endpoint, u8 *buf, u32 len, u32 sync_time
AHB_GIZMO(AHB_AHB_MEM_PREFETCH_CFG1) |= MEM_PREFETCH_ENABLE;
if (direction == USB_DIR_IN)
{
prime_bit = USB2D_ENDPT_STATUS_TX_OFFSET << actual_ep;
bpmp_mmu_maintenance(BPMP_MMU_MAINT_CLEAN_WAY, false);
}
else
prime_bit = USB2D_ENDPT_STATUS_RX_OFFSET << actual_ep;
// Flush data before priming EP.
bpmp_mmu_maintenance(BPMP_MMU_MAINT_CLEAN_WAY, false);
// Prime endpoint.
usbd_otg->regs->endptprime |= prime_bit; // USB2_CONTROLLER_USB2D_ENDPTPRIME.