diff mbox

[PATCHv2,net-next,2/4] cxgb4: For T4, don't read the Firmware Mailbox Control register

Message ID 4985EFDD773FCB459EF7915D2A3621AD93BB822C@nice.asicdesigners.com
State RFC, archived
Delegated to: David Miller
Headers show

Commit Message

Casey Leedom Sept. 30, 2015, 5:53 p.m. UTC 
Hari,

  I think you missed the corresponding change that's needed for the const char *owner[] array.  You need to add an "<unread>" entry so the index of "4" makes sense.

Casey
diff mbox

Patch

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
index 0a87a32..8001619 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
@@ -1134,12 +1134,20 @@  static int mbox_show(struct seq_file *seq, void *v)
        unsigned int mbox = (uintptr_t)seq->private & 7;
        struct adapter *adap = seq->private - mbox;
        void __iomem *addr = adap->regs + PF_REG(mbox, CIM_PF_MAILBOX_DATA_A);
-       unsigned int ctrl_reg = (is_t4(adap->params.chip)
-                                ? CIM_PF_MAILBOX_CTRL_A
-                                : CIM_PF_MAILBOX_CTRL_SHADOW_COPY_A);
-       void __iomem *ctrl = adap->regs + PF_REG(mbox, ctrl_reg);

-       i = MBOWNER_G(readl(ctrl));
+       /* For T4 we don't have a shadow copy of the Mailbox Control register.
+        * And since reading that real register causes a side effect of
+        * granting ownership, we're best of simply not reading it at all.
+        */
+       if (is_t4(adap->params.chip)) {
+               i = 4; /* index of "<unread>" */
+       } else {
+               unsigned int ctrl_reg = CIM_PF_MAILBOX_CTRL_SHADOW_COPY_A;
+               void __iomem *ctrl = adap->regs + PF_REG(mbox, ctrl_reg);
+
+               i = MBOWNER_G(readl(ctrl));
+       }
+
        seq_printf(seq, "mailbox owned by %s\n\n", owner[i]);

        for (i = 0; i < MBOX_LEN; i += 8)