When a PCI device is unplugged reading from the
register will return the value from the state of just
before the device is unplugged.
When a rt61pci device was removed while the txdone
handler was running it ended in a endless loop because
it would run the txdone handler from the same frame
(the one last indicated by STA_CSR4) over and over again.
Check in the loop if the freshly read register value is
the same as the previously one and bail out if this is the case.
Signed-off-by: Ivo van Doorn <IvDoorn@xxxxxxxxx>
---
drivers/net/wireless/rt2x00/rt61pci.c | 22 ++++++++++++++++++----
1 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c
index 6199606..0c53b61 100644
--- a/drivers/net/wireless/rt2x00/rt61pci.c
+++ b/drivers/net/wireless/rt2x00/rt61pci.c
@@ -1801,23 +1801,37 @@ static void rt61pci_txdone(struct rt2x00_dev *rt2x00dev)
struct data_desc *txd;
u32 word;
u32 reg;
+ u32 old_reg;
+ int type;
int index;
int tx_status;
int retry;
+ /*
+ * During each loop we will compare the freshly read
+ * STA_CSR4 register value with the value read from
+ * the previous loop. If the 2 values are equal then
+ * we should stop processing because the chance it
+ * quite big that the device has been unplugged and
+ * we risk going into an endless loop.
+ */
+ old_reg = 0;
+
while (1) {
rt2x00pci_register_read(rt2x00dev, STA_CSR4, ®);
if (!rt2x00_get_field32(reg, STA_CSR4_VALID))
break;
+ if (old_reg == reg)
+ break;
+ old_reg = reg;
+
/*
* Skip this entry when it contains an invalid
* ring identication number.
*/
- ring =
- rt2x00lib_get_ring(rt2x00dev,
- rt2x00_get_field32(reg,
- STA_CSR4_PID_TYPE));
+ type = rt2x00_get_field32(reg, STA_CSR4_PID_TYPE);
+ ring = rt2x00lib_get_ring(rt2x00dev, type);
if (unlikely(!ring))
continue;
--
1.5.3
-
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
