net/sfc/base: ignore error in completion event on MCDIv2 HW

With MCDIv2, the reponse length can be to big to fit into the
CMDDONE_DATALEN field in the MCDI completion event. But rather that
the length being truncated, it can overflow into the CMDDONE_ERRNO
field (this is a longstanding firmware bug). Hence the CMDDONE_ERRNO
field may not be valid.

It isn't necessary to use the value in the CMDDONE_ERRNO field though,
so it can be ignored. The actual error code is already read from the
response header on MCDIv2 capable hardware and stored in emr_rc, so
that can be used instead.

Signed-off-by: Mark Spender <mspender@solarflare.com>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>

diff --git a/drivers/net/sfc/base/efx_mcdi.c b/drivers/net/sfc/base/efx_mcdi.c
index 888a47b..936ad25 100644 (file)
--- a/drivers/net/sfc/base/efx_mcdi.c
+++ b/drivers/net/sfc/base/efx_mcdi.c
@@ -793,9 +793,8 @@ efx_mcdi_ev_cpl(
                        emrp->emr_rc = 0;
                }
        }
-       if (errcode == 0) {
+       if (emrp->emr_rc == 0)
                efx_mcdi_finish_response(enp, emrp);
-       }
 
        emtp->emt_ev_cpl(emtp->emt_context);
 }