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From: <Tudor.Ambarus@microchip.com>
To: <Ludovic.Desroches@microchip.com>, <dan.j.williams@intel.com>,
	<vkoul@kernel.org>
Cc: <dmaengine@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<Tudor.Ambarus@microchip.com>
Subject: [PATCH 02/10] dmaengine: at_hdmac: Drop locking in at_hdmac_alloc_chan_resources()
Date: Thu, 23 Jan 2020 14:03:04 +0000	[thread overview]
Message-ID: <20200123140237.125799-2-tudor.ambarus@microchip.com> (raw)
In-Reply-To: <20200123140237.125799-1-tudor.ambarus@microchip.com>

From: Tudor Ambarus <tudor.ambarus@microchip.com>

There is no need for locking in device_alloc_chan_resources(),
the DMA core takes care of it by using a dma_list_mutex around
the DMA devices.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
 drivers/dma/at_hdmac.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index cad6dcd9cfb5..301bae45cf8d 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1542,10 +1542,8 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
 	struct at_dma		*atdma = to_at_dma(chan->device);
 	struct at_desc		*desc;
 	struct at_dma_slave	*atslave;
-	unsigned long		flags;
 	int			i;
 	u32			cfg;
-	LIST_HEAD(tmp_list);
 
 	dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
 
@@ -1583,14 +1581,11 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
 				"Only %d initial descriptors\n", i);
 			break;
 		}
-		list_add_tail(&desc->desc_node, &tmp_list);
+		list_add_tail(&desc->desc_node, &atchan->free_list);
 	}
 
-	spin_lock_irqsave(&atchan->lock, flags);
 	atchan->descs_allocated = i;
-	list_splice(&tmp_list, &atchan->free_list);
 	dma_cookie_init(chan);
-	spin_unlock_irqrestore(&atchan->lock, flags);
 
 	/* channel parameters */
 	channel_writel(atchan, CFG, cfg);
-- 
2.23.0

  reply	other threads:[~2020-01-23 14:03 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-23 14:03 [PATCH 01/10] dmaengine: at_hdmac: Substitute kzalloc with kmalloc Tudor.Ambarus
2020-01-23 14:03 ` Tudor.Ambarus [this message]
2020-01-23 14:03 ` [PATCH 03/10] dmaengine: at_hdmac: Return err in case the chan is not free at alloc res time Tudor.Ambarus
2020-01-23 14:03 ` [PATCH 04/10] dmaengine: at_hdmac: Drop description for a not defined parameter Tudor.Ambarus
2020-01-23 14:03 ` [PATCH 05/10] dmaengine: at_hdmac: Switch atomic allocations to GFP_NOWAIT Tudor.Ambarus
2020-01-23 14:03 ` [PATCH 06/10] dmaengine: at_hdmac: Fix deadlocks Tudor.Ambarus
2020-01-23 14:03 ` [PATCH 07/10] dmaengine: at_xdmac: Drop always true check Tudor.Ambarus
2020-01-23 14:03 ` [PATCH 08/10] dmaengine: at_xdmac: Drop locking in at_xdmac_alloc_chan_resources() Tudor.Ambarus
2020-01-23 14:03 ` [PATCH 09/10] dmaengine: at_xdmac: GFP_KERNEL for user that can sleep Tudor.Ambarus
2020-01-23 14:03 ` [PATCH 10/10] dmaengine: at_xdmac: Fix locking in tasklet Tudor.Ambarus
2020-02-03  8:24 ` [PATCH 01/10] dmaengine: at_hdmac: Substitute kzalloc with kmalloc Ludovic Desroches
2020-02-25  5:58 ` Vinod Koul

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