RE: [PATCH 2/2] benet: Wait I/O while resuming device

-----Original Message-----
From: Gavin Shan [mailto:shangw@linux.vnet.ibm.com]

After resetting the adapter, the config space register (0x7c) might give fake
information to indicate the f/w is ready. In turn, 0xFF's is always returned while
accessing on I/O space registers. The patch adds more check to make sure the
I/O space is ready for access before accessing that region.

...

+int be_cmd_fw_wait_io(struct be_adapter *adapter) {
+	void __iomem *db = adapter->db + MPU_MAILBOX_DB_OFFSET;
+	int timeout = 0;
+	u32 val;
+
+	if (lancer_chip(adapter))
+		return 0;
+
+	do {
+		val = ioread32(db);
+		if (val != 0xffffffff)
+			return 0;

Wouldn't reading 0xffffffff from a register cause a new EEH flow to be triggered? 

Anyway, the SLIPORT_SEMAPHORE register that returns a valid POST
state *always* is available in the CSR BAR space. This will be for BE2 and BE3
chips. For Skyhawk-R chips config-space/0x7c will work fine.
I can give a patch with these changes in a few days if that works for you....

+
+		dev_info(&adapter->pdev->dev,
+			"Wating for I/O (0x%08x), %ds elapsed\n",
+			val, timeout);
+		if (msleep_interruptible(2000)) {
+			dev_err(&adapter->pdev->dev,
+				"Waiting for I/O aborted\n");
+			return -EIO;
+		}
+		timeout += 2;
+	} while (timeout < 60);
+
+	dev_err(&adapter->pdev->dev, "Timeout waiting for I/O (%d)\n",
timeout);
+	return -1;
+}
+