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Fix LPC17XX and LPC40XX USB race condition 

If a SETUP packet arrives shortly after an IN then the packets will be
processed in the wrong order - SETUP first then IN. This causes
the subsequent control transfer to fail. Fix this problem by processing
IN packets before processing SETUP packets.
pull/5878/head
Russ Butler 2018-01-15 21:09:31 -06:00 committed by Russ Butler
parent 635a82495c
commit eda332cbf8
2 changed files with 38 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
features/unsupported/USBDevice/targets/TARGET_NXP/USBHAL_LPC17.cpp
View File

@ -590,6 +590,25 @@ void USBHAL::usbisr(void) {
if (LPC_USB->USBDevIntSt & EP_SLOW) { if (LPC_USB->USBDevIntSt & EP_SLOW) {
// (Slow) Endpoint Interrupt // (Slow) Endpoint Interrupt
// Process IN packets before SETUP packets
// Note - order of OUT and SETUP does not matter as OUT packets
// are clobbered by SETUP packets and thus ignored.
//
// A SETUP packet can arrive at any time where as an IN packet is
// only sent after calling EP0write and an OUT packet after EP0read.
// The functions EP0write and EP0read are called only in response to
// a setup packet or IN/OUT packets sent in response to that
// setup packet. Therefore, if an IN or OUT packet is pending
// at the same time as a SETUP packet, the IN or OUT packet belongs
// to the previous control transfer and should either be processed
// before the SETUP packet (in the case of IN) or dropped (in the
// case of OUT as SETUP clobbers the OUT data).
if (LPC_USB->USBEpIntSt & EP(EP0IN)) {
selectEndpointClearInterrupt(EP0IN);
LPC_USB->USBDevIntClr = EP_SLOW;
EP0in();
}
// Process each endpoint interrupt // Process each endpoint interrupt
if (LPC_USB->USBEpIntSt & EP(EP0OUT)) { if (LPC_USB->USBEpIntSt & EP(EP0OUT)) {
if (selectEndpointClearInterrupt(EP0OUT) & SIE_SE_STP) { if (selectEndpointClearInterrupt(EP0OUT) & SIE_SE_STP) {
@ -601,12 +620,6 @@ void USBHAL::usbisr(void) {
LPC_USB->USBDevIntClr = EP_SLOW; LPC_USB->USBDevIntClr = EP_SLOW;
} }
if (LPC_USB->USBEpIntSt & EP(EP0IN)) {
selectEndpointClearInterrupt(EP0IN);
LPC_USB->USBDevIntClr = EP_SLOW;
EP0in();
}
for (uint8_t num = 2; num < 16*2; num++) { for (uint8_t num = 2; num < 16*2; num++) {
if (LPC_USB->USBEpIntSt & EP(num)) { if (LPC_USB->USBEpIntSt & EP(num)) {
selectEndpointClearInterrupt(num); selectEndpointClearInterrupt(num);

25
features/unsupported/USBDevice/targets/TARGET_NXP/USBHAL_LPC40.cpp
View File

@ -595,6 +595,25 @@ void USBHAL::usbisr(void) {
if (LPC_USB->DevIntSt & EP_SLOW) { if (LPC_USB->DevIntSt & EP_SLOW) {
// (Slow) Endpoint Interrupt // (Slow) Endpoint Interrupt
// Process IN packets before SETUP packets
// Note - order of OUT and SETUP does not matter as OUT packets
// are clobbered by SETUP packets and thus ignored.
//
// A SETUP packet can arrive at any time where as an IN packet is
// only sent after calling EP0write and an OUT packet after EP0read.
// The functions EP0write and EP0read are called only in response to
// a setup packet or IN/OUT packets sent in response to that
// setup packet. Therefore, if an IN or OUT packet is pending
// at the same time as a SETUP packet, the IN or OUT packet belongs
// to the previous control transfer and should either be processed
// before the SETUP packet (in the case of IN) or dropped (in the
// case of OUT as SETUP clobbers the OUT data).
if (LPC_USB->EpIntSt & EP(EP0IN)) {
selectEndpointClearInterrupt(EP0IN);
LPC_USB->DevIntClr = EP_SLOW;
EP0in();
}
// Process each endpoint interrupt // Process each endpoint interrupt
if (LPC_USB->EpIntSt & EP(EP0OUT)) { if (LPC_USB->EpIntSt & EP(EP0OUT)) {
if (selectEndpointClearInterrupt(EP0OUT) & SIE_SE_STP) { if (selectEndpointClearInterrupt(EP0OUT) & SIE_SE_STP) {
@ -606,12 +625,6 @@ void USBHAL::usbisr(void) {
LPC_USB->DevIntClr = EP_SLOW; LPC_USB->DevIntClr = EP_SLOW;
} }
if (LPC_USB->EpIntSt & EP(EP0IN)) {
selectEndpointClearInterrupt(EP0IN);
LPC_USB->DevIntClr = EP_SLOW;
EP0in();
}
for (uint8_t num = 2; num < 16*2; num++) { for (uint8_t num = 2; num < 16*2; num++) {
if (LPC_USB->EpIntSt & EP(num)) { if (LPC_USB->EpIntSt & EP(num)) {
selectEndpointClearInterrupt(num); selectEndpointClearInterrupt(num);