firewire: ohci: dump_stack() for PHY regs read/write failures

A stack trace is an invaluable tool in determining the basis
and cause of PHY regs read/write failures.

Include PHY reg addr (and value for writes) in the diagnostic.

[Stefan R:  changed whitespace]

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index c64b4801adaa..9e1db6490b9a 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -572,7 +572,8 @@ static int read_phy_reg(struct fw_ohci *ohci, int addr)
                 if (i >= 3)
                         msleep(1);
         }
-        ohci_err(ohci, "failed to read phy reg\n");
+        ohci_err(ohci, "failed to read phy reg %d\n", addr);
+        dump_stack();
 
         return -EBUSY;
 }
@@ -594,7 +595,8 @@ static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
                 if (i >= 3)
                         msleep(1);
         }
-        ohci_err(ohci, "failed to write phy reg\n");
+        ohci_err(ohci, "failed to write phy reg %d, val %u\n", addr, val);
+        dump_stack();
 
         return -EBUSY;
 }