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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 08/10] dmaengine: at_xdmac: Drop locking in at_xdmac_alloc_chan_resources()
Date: Thu, 23 Jan 2020 14:03:14 +0000	[thread overview]
Message-ID: <20200123140237.125799-8-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_xdmac.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 3d6e84def7a6..8fb01bc90ba7 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1820,22 +1820,17 @@ static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)
 	struct at_xdmac_chan	*atchan = to_at_xdmac_chan(chan);
 	struct at_xdmac_desc	*desc;
 	int			i;
-	unsigned long		flags;
-
-	spin_lock_irqsave(&atchan->lock, flags);
 
 	if (at_xdmac_chan_is_enabled(atchan)) {
 		dev_err(chan2dev(chan),
 			"can't allocate channel resources (channel enabled)\n");
-		i = -EIO;
-		goto spin_unlock;
+		return -EIO;
 	}
 
 	if (!list_empty(&atchan->free_descs_list)) {
 		dev_err(chan2dev(chan),
 			"can't allocate channel resources (channel not free from a previous use)\n");
-		i = -EIO;
-		goto spin_unlock;
+		return -EIO;
 	}
 
 	for (i = 0; i < init_nr_desc_per_channel; i++) {
@@ -1852,8 +1847,6 @@ static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)
 
 	dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
 
-spin_unlock:
-	spin_unlock_irqrestore(&atchan->lock, flags);
 	return i;
 }
 
-- 
2.23.0

  parent 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 ` [PATCH 02/10] dmaengine: at_hdmac: Drop locking in at_hdmac_alloc_chan_resources() Tudor.Ambarus
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 ` Tudor.Ambarus [this message]
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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