Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754264Ab3GUG70 (ORCPT ); Sun, 21 Jul 2013 02:59:26 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:39747 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752336Ab3GUG7W (ORCPT ); Sun, 21 Jul 2013 02:59:22 -0400 From: Joel Fernandes To: Tony Lindgren , Sekhar Nori , Santosh Shilimkar , Sricharan R , Rajendra Nayak , Lokesh Vutla , Matt Porter , Grant Likely , Rob Herring , Vinod Koul , Dan Williams , Mark Brown , Benoit Cousson , Russell King , Arnd Bergmann , Balaji TK , Gururaja Hebbar , Chris Ball , Jason Kridner CC: Linux OMAP List , Linux ARM Kernel List , Linux DaVinci Kernel List , Linux Kernel Mailing List , Linux MMC List , Joel Fernandes Subject: [RFC 5/5] DMA: EDMA: Leave linked to Null slot instead of DUMMY slot Date: Sun, 21 Jul 2013 01:58:45 -0500 Message-ID: <1374389925-32667-1-git-send-email-joelf@ti.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1522 Lines: 41 Dummy slot has been used as a way for missed-events not to be reported as missing. This has been particularly troublesome for cases where we might want to temporarily pause all incoming events. For EDMA DMAC, there is no way to do any such pausing of events as the occurence of the "next" event is not software controlled. Using "edma_pause" in IRQ handlers doesn't help as by then the event in concern from the slave is already missed. Linking a dummy slot, is seen to absorb these events which we didn't want to miss. So we don't link to dummy, but instead leave it linked to NULL set, allow an error condition and detect the channel that missed it. Signed-off-by: Joel Fernandes --- drivers/dma/edma.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index b0b5bcd..e9f1f27 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -160,9 +160,6 @@ static void edma_execute(struct edma_chan *echan) /* Link to the previous slot if not the last set */ if (i != (total_process - 1)) edma_link(echan->slot[i], echan->slot[i+1]); - /* Final pset links to the dummy pset */ - else - edma_link(echan->slot[i], echan->ecc->dummy_slot); } edesc->total_processed += total_process; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/