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dmaengine: bcm2835: Drop gratuitous list deletion
authorLukas Wunner <lukas@wunner.de>
Wed, 23 Jan 2019 08:26:00 +0000 (09:26 +0100)
committerVinod Koul <vkoul@kernel.org>
Mon, 4 Feb 2019 07:11:32 +0000 (12:41 +0530)
The BCM2835 DMA driver deletes a channel from a list upon termination
without having added it to a list first.  Moreover that operation is
protected by a spinlock which isn't taken anywhere else.  These appear
to be remnants of an older version of the driver which accidentally
got mainlined.  Remove the dead code.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Frank Pavlic <f.pavlic@kunbus.de>
Cc: Martin Sperl <kernel@martin.sperl.org>
Cc: Florian Meier <florian.meier@koalo.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Florian Kauer <florian.kauer@koalo.de>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
drivers/dma/bcm2835-dma.c

index 6d66e23..138bda3 100644 (file)
@@ -42,7 +42,6 @@
 
 struct bcm2835_dmadev {
        struct dma_device ddev;
-       spinlock_t lock;
        void __iomem *base;
        struct device_dma_parameters dma_parms;
 };
@@ -64,7 +63,6 @@ struct bcm2835_cb_entry {
 
 struct bcm2835_chan {
        struct virt_dma_chan vc;
-       struct list_head node;
 
        struct dma_slave_config cfg;
        unsigned int dreq;
@@ -777,17 +775,11 @@ static int bcm2835_dma_slave_config(struct dma_chan *chan,
 static int bcm2835_dma_terminate_all(struct dma_chan *chan)
 {
        struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
-       struct bcm2835_dmadev *d = to_bcm2835_dma_dev(c->vc.chan.device);
        unsigned long flags;
        LIST_HEAD(head);
 
        spin_lock_irqsave(&c->vc.lock, flags);
 
-       /* Prevent this channel being scheduled */
-       spin_lock(&d->lock);
-       list_del_init(&c->node);
-       spin_unlock(&d->lock);
-
        /* stop DMA activity */
        if (c->desc) {
                vchan_terminate_vdesc(&c->desc->vd);
@@ -820,7 +812,6 @@ static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id,
 
        c->vc.desc_free = bcm2835_dma_desc_free;
        vchan_init(&c->vc, &d->ddev);
-       INIT_LIST_HEAD(&c->node);
 
        c->chan_base = BCM2835_DMA_CHANIO(d->base, chan_id);
        c->ch = chan_id;
@@ -923,7 +914,6 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
        od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
        od->ddev.dev = &pdev->dev;
        INIT_LIST_HEAD(&od->ddev.channels);
-       spin_lock_init(&od->lock);
 
        platform_set_drvdata(pdev, od);