net: cadence_gem: Fix Tx descriptor update

The local variable "desc" was being used to read-modify-write the
first descriptor (of a multi-desc packet) upon packet completion.
desc however continues to be used by the code as the current
descriptor. Give this first desc RMW it's own local variable to
avoid trampling.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This commit is contained in:
Peter Crosthwaite 2014-05-26 01:37:47 -07:00 committed by Michael Tokarev
parent 3334e929ae
commit 6ab57a6b80
1 changed files with 7 additions and 5 deletions

View File

@ -911,14 +911,16 @@ static void gem_transmit(GemState *s)
/* Last descriptor for this packet; hand the whole thing off */
if (tx_desc_get_last(desc)) {
unsigned desc_first[2];
/* Modify the 1st descriptor of this packet to be owned by
* the processor.
*/
cpu_physical_memory_read(s->tx_desc_addr,
(uint8_t *)&desc[0], sizeof(desc));
tx_desc_set_used(desc);
cpu_physical_memory_write(s->tx_desc_addr,
(uint8_t *)&desc[0], sizeof(desc));
cpu_physical_memory_read(s->tx_desc_addr, (uint8_t *)desc_first,
sizeof(desc_first));
tx_desc_set_used(desc_first);
cpu_physical_memory_write(s->tx_desc_addr, (uint8_t *)desc_first,
sizeof(desc_first));
/* Advance the hardare current descriptor past this packet */
if (tx_desc_get_wrap(desc)) {
s->tx_desc_addr = s->regs[GEM_TXQBASE];