Re: [PATCH] qede: fix CONFIG_INFINIBAND_QEDR=m build error

On Thursday, October 13, 2016 8:50:21 AM CEST Mintz, Yuval wrote:

quoted

 config INFINIBAND_QEDR
-	tristate "QLogic qede RoCE sources [debug]"
+	bool "QLogic qede RoCE sources [debug]"

Given that the qedr submission is going to turn this back into a tristate,
are you certain this is a good thing [from compilation coverage perspective]?

I haven't seen that submission, I just looked at the current
state in linux-next. If we want this to be a separately loadable
module, that seems fine too, but then we should fix the Makefile
to do that, and add the necessary Kconfig magic to ensure that
INFINIBAND_QED cannot be built-in when INFINIBAND_QEDR=m.

quoted

-		if (cond)
+		if (IS_ENABLED(CONFIG_INFINIBAND_QEDR) && cond)
		qed_rdma_dpm_bar(p_hwfn, p_ptt);

Why not simply fix the qed_roce.h empty implementation?

Mainly for consistency: we have a couple of interfaces that
are called from the qed driver that are implemented in
qed_roce.c. We can either use a 'static inline' helper for
all of them, or use if(IS_ENABLED()) everywhere. Since this
was the only function that had a helper and that helper
was defined incorrectly, I went with the second option.

quoted

-#if IS_ENABLED(CONFIG_INFINIBAND_QEDR)
 	/* Roce CNQ each requires: 1 status block + 1 CNQ. We divide the
 	 * status blocks equally between L2 / RoCE but with consideration as
 	 * to how many l2 queues / cnqs we have
 	 */
-	if (p_hwfn->hw_info.personality == QED_PCI_ETH_ROCE) {
+	if (IS_ENABLED(CONFIG_INFINIBAND_QEDR) &&
+	    p_hwfn->hw_info.personality == QED_PCI_ETH_ROCE) {
 		num_features++;

 		feat_num[QED_RDMA_CNQ] =
 			min_t(u32, RESC_NUM(p_hwfn, QED_SB) /
num_features,
 			      RESC_NUM(p_hwfn, QED_RDMA_CNQ_RAM));
 	}
-#endif

Is there any non-cosmetic gain here?
I would gain that having the comment under the #ifdef is more meaningful
than having the check in the actual condition.

No, it's purely cosmetic. Moving the comment inside of the if()
block seems fine, I just didn't want to touch that as it was
unrelated.

quoted

-#if IS_ENABLED(CONFIG_INFINIBAND_QEDR)
+	if (!IS_ENABLED(CONFIG_INFINIBAND_QEDR))
+		return 0;
+
 	num_l2_queues = 0;
 	for_each_hwfn(cdev, i)
 		num_l2_queues += FEAT_NUM(&cdev->hwfns[i],
QED_PF_L2_QUE); @@ -738,7 +736,6 @@ static int
qed_slowpath_setup_int(struct qed_dev *cdev,
 	DP_VERBOSE(cdev, QED_MSG_RDMA, "roce_msix_cnt=%d
roce_msix_base=%d\n",
 		   cdev->int_params.rdma_msix_cnt,
 		   cdev->int_params.rdma_msix_base);
-#endif

While I don't mind, you could have argued is that we're not
removing enough, not too much.
I.e., perhaps the rdma_msix_* fields should also have been
ifdef-ed instead. [in which case this solution would not have worked]

That would add even more #ifdefs though.

	Arnd