diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/portable/raspberrypi/rp2040/dcd_rp2040.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/src/portable/raspberrypi/rp2040/dcd_rp2040.c b/src/portable/raspberrypi/rp2040/dcd_rp2040.c index e8cee73fd..51174f709 100644 --- a/src/portable/raspberrypi/rp2040/dcd_rp2040.c +++ b/src/portable/raspberrypi/rp2040/dcd_rp2040.c @@ -217,6 +217,18 @@ static void __tusb_irq_path_func(hw_handle_buff_status)(void) TU_ATTR_ALWAYS_INLINE static inline void reset_ep0_pid(void) { + // Abort any transactions from a prior control transfer, because + // receiving SETUP doesn't reset buffer control state. This works around + // a possible USB hardware erratum. + + // With this workaround a race window still exists, but smaller. + // ABORT flag is unusable prior to hardware B2 (RP2040-E2), so a larger + // race window exists for B1 and earlier. + if (rp2040_chip_version() >= 2) { + usb_hw_set->abort = 0x3; + while ((usb_hw->abort_done & 0x3) != 0x3) + ; + } // If we have finished this transfer on EP0 set pid back to 1 for next // setup transfer. Also clear a stall in case uint8_t addrs[] = {0x0, 0x80}; @@ -224,6 +236,25 @@ TU_ATTR_ALWAYS_INLINE static inline void reset_ep0_pid(void) { struct hw_endpoint *ep = hw_endpoint_get_by_addr(addrs[i]); ep->next_pid = 1u; + // Reset the buffer control now to minimize race conditions + _hw_endpoint_buffer_control_set_value32(ep, USB_BUF_CTRL_DATA1_PID | USB_BUF_CTRL_SEL); + // Explicit delay, because the one in + // _hw_endpoint_buffer_control_set_value32 is only to set AVAILABLE + __asm volatile ( + "b 1f\n" + "1: b 1f\n" + "1: b 1f\n" + "1: b 1f\n" + "1: b 1f\n" + "1: b 1f\n" + "1:\n" + : : : "memory"); + // Make sure local ep state matches peripheral + hw_endpoint_reset_transfer(ep); + } + if (rp2040_chip_version() >= 2) { + usb_hw_clear->abort = 0x3; + usb_hw_clear->abort_done = 0x3; } } |