RE: [PATCH net-next 1/8] net: hns3: Add HNS3 VF IMP(Integrated Management Proc) cmd interface

Hi Dave,

-----Original Message-----
From: David Miller [mailto:davem@davemloft.net]
Sent: Tuesday, December 05, 2017 4:38 PM
To: Salil Mehta <redacted>
Cc: Zhuangyuzeng (Yisen) <redacted>; lipeng (Y)
[off-list ref]; mehta.salil.lnk@gmail.com;
netdev@vger.kernel.org; linux-kernel@vger.kernel.org; linux-
rdma@vger.kernel.org; Linuxarm [off-list ref]
Subject: Re: [PATCH net-next 1/8] net: hns3: Add HNS3 VF IMP(Integrated
Management Proc) cmd interface

From: Salil Mehta <redacted>
Date: Sun, 3 Dec 2017 12:33:00 +0000

quoted

+static int hclgevf_ring_space(struct hclgevf_cmq_ring *ring)
+{
+	int ntu = ring->next_to_use;
+	int ntc = ring->next_to_clean;
+	int used = (ntu - ntc + ring->desc_num) % ring->desc_num;

Order local variables from longest to shortest line, please.

This one skipped my eyes. Will fix. Thanks.

Audit your entire submission for this issue.

Sure, will do. 

quoted

+static int hclgevf_cmd_csq_done(struct hclgevf_hw *hw)
+{
+	u32 head = hclgevf_read_dev(hw, HCLGEVF_NIC_CSQ_HEAD_REG);
+	return head == hw->cmq.csq.next_to_use;
+}

Please return bool from this function.

Agreed. Should have been bool here. Will fix.

quoted

+void hclgevf_cmd_setup_basic_desc(struct hclgevf_desc *desc,
+				  enum hclgevf_opcode_type opcode, bool

is_read)

quoted

+{
+	memset((void *)desc, 0, sizeof(struct hclgevf_desc));

You never need casts like this, when the functions argument is void any
pointer can be passed in as-is.

Agreed. Will remove this.

quoted

+
+	/* If the command is sync, wait for the firmware to write back,
+	 * if multi descriptors to be sent, use the first one to check
+	 */
+	if (HCLGEVF_SEND_SYNC(le16_to_cpu(desc->flag))) {
+		do {
+			if (hclgevf_cmd_csq_done(hw))
+				break;
+			udelay(1);
+			timeout++;
+		} while (timeout < hw->cmq.tx_timeout);
+	}

This is potentially a long timeout with a spinlock held.  Consider
using
sleeping and completions.

I guess you meant 1 usec X (hw->cmq.tx_timeout = 200) times the delay
is large - right?

Will review it again. 

Thanks.
Salil