firewire: ohci: fix PHY reg access after card ejection
Detect and handle ejection of FireWire CardBus cards in PHY register
accesses:
- The last attempt of firewire-core to reset the bus during shutdown
caused a spurious "firewire_ohci: failed to write phy reg" error
message in the log. Skip this message as well as the prior retry
loop that needlessly took 100 milliseconds.
- In the unlikely case that a PHY register was read right after card
ejection, a bogus value was obtained and possibly acted upon.
Instead, fail the read attempt.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index a818dc8..4485988 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -527,6 +527,9 @@
reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
for (i = 0; i < 3 + 100; i++) {
val = reg_read(ohci, OHCI1394_PhyControl);
+ if (!~val)
+ return -ENODEV; /* Card was ejected. */
+
if (val & OHCI1394_PhyControl_ReadDone)
return OHCI1394_PhyControl_ReadData(val);
@@ -550,6 +553,9 @@
OHCI1394_PhyControl_Write(addr, val));
for (i = 0; i < 3 + 100; i++) {
val = reg_read(ohci, OHCI1394_PhyControl);
+ if (!~val)
+ return -ENODEV; /* Card was ejected. */
+
if (!(val & OHCI1394_PhyControl_WritePending))
return 0;