diff options
Diffstat (limited to 'drivers/net/cxgb4vf')
| -rw-r--r-- | drivers/net/cxgb4vf/t4vf_hw.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/net/cxgb4vf/t4vf_hw.c b/drivers/net/cxgb4vf/t4vf_hw.c index e4bec78c8e3f..0f51c80475ce 100644 --- a/drivers/net/cxgb4vf/t4vf_hw.c +++ b/drivers/net/cxgb4vf/t4vf_hw.c @@ -147,9 +147,20 @@ int t4vf_wr_mbox_core(struct adapter *adapter, const void *cmd, int size, /* * Write the command array into the Mailbox Data register array and * transfer ownership of the mailbox to the firmware. + * + * For the VFs, the Mailbox Data "registers" are actually backed by + * T4's "MA" interface rather than PL Registers (as is the case for + * the PFs). Because these are in different coherency domains, the + * write to the VF's PL-register-backed Mailbox Control can race in + * front of the writes to the MA-backed VF Mailbox Data "registers". + * So we need to do a read-back on at least one byte of the VF Mailbox + * Data registers before doing the write to the VF Mailbox Control + * register. */ for (i = 0, p = cmd; i < size; i += 8) t4_write_reg64(adapter, mbox_data + i, be64_to_cpu(*p++)); + t4_read_reg(adapter, mbox_data); /* flush write */ + t4_write_reg(adapter, mbox_ctl, MBMSGVALID | MBOWNER(MBOX_OWNER_FW)); t4_read_reg(adapter, mbox_ctl); /* flush write */ |