sfc: QT2025C: Add error message for suspected bad SFP+ cables

Some cables have EEPROMs that conflict with the PHY's on-board EEPROM
so it cannot load firmware.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/net/sfc/qt202x_phy.c b/drivers/net/sfc/qt202x_phy.c
index 326ffa49fbd2..ff8f0a417fa3 100644
--- a/drivers/net/sfc/qt202x_phy.c
+++ b/drivers/net/sfc/qt202x_phy.c
@@ -87,8 +87,14 @@ static int qt2025c_wait_heartbeat(struct efx_nic *efx)
                         old_counter = counter;
                 else if (counter != old_counter)
                         break;
-                if (time_after(jiffies, timeout))
+                if (time_after(jiffies, timeout)) {
+                        /* Some cables have EEPROMs that conflict with the
+                         * PHY's on-board EEPROM so it cannot load firmware */
+                        EFX_ERR(efx, "If an SFP+ direct attach cable is"
+                                " connected, please check that it complies"
+                                " with the SFP+ specification\n");
                         return -ETIMEDOUT;
+                }
                 msleep(QT2025C_HEARTB_WAIT);
         }