Commit 8534f32c authored by Eilon Greenstein's avatar Eilon Greenstein Committed by David S. Miller
Browse files

bnx2x: napi_poll budget check 



Check the napi_poll budget only when updating it. Also add a comment to explain
the rmb

Signed-off-by: default avatarEilon Greenstein <eilong@broadcom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7961f791

drivers/net/bnx2x_main.c

+18 −4
Original line number Diff line number Diff line
@@ -10068,14 +10068,27 @@ static int bnx2x_poll(struct napi_struct *napi, int budget) 
	if (bnx2x_has_tx_work(fp))

		bnx2x_tx_int(fp);



	if (bnx2x_has_rx_work(fp))

	if (bnx2x_has_rx_work(fp)) {

		work_done = bnx2x_rx_int(fp, budget);



	rmb(); /* BNX2X_HAS_WORK() reads the status block */



		/* must not complete if we consumed full budget */

	if ((work_done < budget) && !BNX2X_HAS_WORK(fp)) {

		if (work_done >= budget)

			goto poll_again;

	}



	/* BNX2X_HAS_WORK() reads the status block, thus we need to

	 * ensure that status block indices have been actually read

	 * (bnx2x_update_fpsb_idx) prior to this check (BNX2X_HAS_WORK)

	 * so that we won't write the "newer" value of the status block to IGU

	 * (if there was a DMA right after BNX2X_HAS_WORK and

	 * if there is no rmb, the memory reading (bnx2x_update_fpsb_idx)

	 * may be postponed to right before bnx2x_ack_sb). In this case

	 * there will never be another interrupt until there is another update

	 * of the status block, while there is still unhandled work.

	 */

	rmb();



	if (!BNX2X_HAS_WORK(fp)) {

#ifdef BNX2X_STOP_ON_ERROR

poll_panic:

#endif
@@ -10087,6 +10100,7 @@ static int bnx2x_poll(struct napi_struct *napi, int budget) 
			     le16_to_cpu(fp->fp_c_idx), IGU_INT_ENABLE, 1);

	}



poll_again:

	return work_done;

}