Aren/haiku
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

We cannot use the condition codes to determine if a transfer descriptor is

Browse Source 
processed. The controller may initialize it to any value when starting to
process the descriptor. If a controller did that it was possible that we thought
a transfer was already done even if it actually just started. Transfers would
then return that weren't processed, returning uninitialized buffers.
Instead of relying on the condition codes we now check that the head and tail
pointers are the same. This guarantees that all transfer descriptors of the
endpoint at hand are completed.
Reverted r32534 again as this one fixes the problem for real. The same things
that were mentioned there could happen here essentially, so in the worst case
the device or controller could stall because of freeing in-use structures.
Fixes #4067.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32551 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Michael Lotz 2009-08-21 00:14:50 +00:00
parent 66dde0a85d
commit c265fd23cd
1 changed files with 17 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
src/add-ons/kernel/busses/usb/ohci.cpp
View File

@ -888,6 +888,18 @@ OHCI::_FinishTransfers()
ohci_general_td *descriptor = transfer->first_descriptor;
status_t callbackStatus = B_OK;
ohci_endpoint_descriptor *endpoint = transfer->endpoint;
if ((endpoint->head_physical_descriptor & OHCI_ENDPOINT_HEAD_MASK)
!= endpoint->tail_physical_descriptor) {
// there are still active transfers on this endpoint, we need
// to wait for all of them to complete, otherwise we'd read
// a potentially bogus data toggle value below
TRACE("endpoint %p still has active tds\n", endpoint);
lastTransfer = transfer;
transfer = transfer->link;
continue;
}
while (descriptor && !transfer->canceled) {
uint32 status = OHCI_TD_GET_CONDITION_CODE(descriptor->flags);
if (status == OHCI_TD_CONDITION_NOT_ACCESSED) {
@ -899,7 +911,6 @@ OHCI::_FinishTransfers()
if (status != OHCI_TD_CONDITION_NO_ERROR) {
// an error occured, but we must ensure that the td
// was actually done
ohci_endpoint_descriptor *endpoint = transfer->endpoint;
if (endpoint->head_physical_descriptor & OHCI_ENDPOINT_HALTED) {
// the endpoint is halted, this guaratees us that this
// descriptor has passed (we don't know if the endpoint
@ -1035,7 +1046,7 @@ OHCI::_FinishTransfers()
// get the last data toggle and store it for next time
transfer->transfer->TransferPipe()->SetDataToggle(
(transfer->endpoint->head_physical_descriptor
(endpoint->head_physical_descriptor
& OHCI_ENDPOINT_TOGGLE_CARRY) != 0);
if (transfer->transfer->IsFragmented()) {
@ -1078,7 +1089,7 @@ status_t
OHCI::_SubmitRequest(Transfer *transfer)
{
usb_request_data *requestData = transfer->RequestData();
bool directionIn = (requestData->RequestType & USB_REQTYPE_DEVICE_IN) > 0;
bool directionIn = (requestData->RequestType & USB_REQTYPE_DEVICE_IN) != 0;
ohci_general_td *setupDescriptor
= _CreateGeneralDescriptor(sizeof(usb_request_data));
@ -1231,7 +1242,7 @@ OHCI::_SwitchEndpointTail(ohci_endpoint_descriptor *endpoint,
tail->next_logical_descriptor = first->next_logical_descriptor;
// the first descriptor becomes the new tail
first->flags = OHCI_TD_SET_CONDITION_CODE(OHCI_TD_CONDITION_NOT_ACCESSED);
first->flags = 0;
first->buffer_physical = 0;
first->next_physical_descriptor = 0;
first->last_physical_byte_address = 0;
@ -1247,6 +1258,7 @@ OHCI::_SwitchEndpointTail(ohci_endpoint_descriptor *endpoint,
// update the endpoint tail pointer to reflect the change
endpoint->tail_logical_descriptor = first;
endpoint->tail_physical_descriptor = (uint32)first->physical_address;
TRACE("switched tail from %p to %p\n", tail, first);
#if 0
_PrintEndpoint(endpoint);
@ -1410,7 +1422,7 @@ OHCI::_InsertEndpointForPipe(Pipe *pipe)
return B_ERROR;
} else {
ohci_general_td *tail = _CreateGeneralDescriptor(0);
tail->flags = OHCI_TD_SET_CONDITION_CODE(OHCI_TD_CONDITION_NOT_ACCESSED);
tail->flags = 0;
endpoint->tail_logical_descriptor = tail;
endpoint->head_physical_descriptor = tail->physical_address;
endpoint->tail_physical_descriptor = tail->physical_address;