dmaengine: at_xdmac: lock fixes
Using _bh variant for spin locks causes this kind of warning: Starting logging: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 3 at /ssd_drive/linux/kernel/softirq.c:151 __local_bh_enable_ip+0xe8/0xf4() Modules linked in: CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 4.1.0-rc2+ #94 Hardware name: Atmel SAMA5 [<c0013c04>] (unwind_backtrace) from [<c00118a4>] (show_stack+0x10/0x14) [<c00118a4>] (show_stack) from [<c001bbcc>] (warn_slowpath_common+0x80/0xac) [<c001bbcc>] (warn_slowpath_common) from [<c001bc14>] (warn_slowpath_null+0x1c/0x24) [<c001bc14>] (warn_slowpath_null) from [<c001e28c>] (__local_bh_enable_ip+0xe8/0xf4) [<c001e28c>] (__local_bh_enable_ip) from [<c01fdbd0>] (at_xdmac_device_terminate_all+0xf4/0x100) [<c01fdbd0>] (at_xdmac_device_terminate_all) from [<c02221a4>] (atmel_complete_tx_dma+0x34/0xf4) [<c02221a4>] (atmel_complete_tx_dma) from [<c01fe4ac>] (at_xdmac_tasklet+0x14c/0x1ac) [<c01fe4ac>] (at_xdmac_tasklet) from [<c001de58>] (tasklet_action+0x68/0xb4) [<c001de58>] (tasklet_action) from [<c001dfdc>] (__do_softirq+0xfc/0x238) [<c001dfdc>] (__do_softirq) from [<c001e140>] (run_ksoftirqd+0x28/0x34) [<c001e140>] (run_ksoftirqd) from [<c0033a3c>] (smpboot_thread_fn+0x138/0x18c) [<c0033a3c>] (smpboot_thread_fn) from [<c0030e7c>] (kthread+0xdc/0xf0) [<c0030e7c>] (kthread) from [<c000f480>] (ret_from_fork+0x14/0x34) ---[ end trace b57b14a99c1d8812 ]--- It comes from the fact that devices can called some code from the DMA controller with irq disabled. _bh variant is not intended to be used in this case since it can enable irqs. Switch to irqsave/irqrestore variant to avoid this situation. Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Cc: stable@vger.kernel.org # 4.0 and later Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Ludovic Desroches
Vinod Koul
parent
d4a4f75cd8
commit
4c374fc7ce
1 changed files with 43 additions and 32 deletions
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@ -415,8 +415,9 @@ static dma_cookie_t at_xdmac_tx_submit(struct dma_async_tx_descriptor *tx)
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struct at_xdmac_desc *desc = txd_to_at_desc(tx);
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struct at_xdmac_chan *atchan = to_at_xdmac_chan(tx->chan);
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dma_cookie_t cookie;
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unsigned long irqflags;
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, irqflags);
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cookie = dma_cookie_assign(tx);
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dev_vdbg(chan2dev(tx->chan), "%s: atchan 0x%p, add desc 0x%p to xfers_list\n",
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@ -425,7 +426,7 @@ static dma_cookie_t at_xdmac_tx_submit(struct dma_async_tx_descriptor *tx)
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if (list_is_singular(&atchan->xfers_list))
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at_xdmac_start_xfer(atchan, desc);
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, irqflags);
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return cookie;
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}
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@ -563,6 +564,8 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
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struct scatterlist *sg;
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int i;
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unsigned int xfer_size = 0;
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unsigned long irqflags;
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struct dma_async_tx_descriptor *ret = NULL;
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if (!sgl)
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return NULL;
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@ -578,7 +581,7 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
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flags);
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/* Protect dma_sconfig field that can be modified by set_slave_conf. */
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, irqflags);
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/* Prepare descriptors. */
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for_each_sg(sgl, sg, sg_len, i) {
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@ -589,8 +592,7 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
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mem = sg_dma_address(sg);
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if (unlikely(!len)) {
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dev_err(chan2dev(chan), "sg data length is zero\n");
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spin_unlock_bh(&atchan->lock);
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return NULL;
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goto spin_unlock;
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}
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dev_dbg(chan2dev(chan), "%s: * sg%d len=%u, mem=0x%08x\n",
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__func__, i, len, mem);
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@ -600,8 +602,7 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
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dev_err(chan2dev(chan), "can't get descriptor\n");
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if (first)
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list_splice_init(&first->descs_list, &atchan->free_descs_list);
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spin_unlock_bh(&atchan->lock);
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return NULL;
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goto spin_unlock;
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}
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/* Linked list descriptor setup. */
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@ -645,13 +646,15 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
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xfer_size += len;
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}
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spin_unlock_bh(&atchan->lock);
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first->tx_dma_desc.flags = flags;
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first->xfer_size = xfer_size;
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first->direction = direction;
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ret = &first->tx_dma_desc;
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return &first->tx_dma_desc;
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spin_unlock:
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spin_unlock_irqrestore(&atchan->lock, irqflags);
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return ret;
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}
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static struct dma_async_tx_descriptor *
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@ -664,6 +667,7 @@ at_xdmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
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struct at_xdmac_desc *first = NULL, *prev = NULL;
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unsigned int periods = buf_len / period_len;
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int i;
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unsigned long irqflags;
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dev_dbg(chan2dev(chan), "%s: buf_addr=%pad, buf_len=%zd, period_len=%zd, dir=%s, flags=0x%lx\n",
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__func__, &buf_addr, buf_len, period_len,
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@ -682,16 +686,16 @@ at_xdmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
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for (i = 0; i < periods; i++) {
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struct at_xdmac_desc *desc = NULL;
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, irqflags);
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desc = at_xdmac_get_desc(atchan);
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if (!desc) {
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dev_err(chan2dev(chan), "can't get descriptor\n");
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if (first)
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list_splice_init(&first->descs_list, &atchan->free_descs_list);
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, irqflags);
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return NULL;
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}
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, irqflags);
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dev_dbg(chan2dev(chan),
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"%s: desc=0x%p, tx_dma_desc.phys=%pad\n",
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__func__, desc, &desc->tx_dma_desc.phys);
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@ -766,6 +770,7 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
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| AT_XDMAC_CC_SIF(0)
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| AT_XDMAC_CC_MBSIZE_SIXTEEN
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| AT_XDMAC_CC_TYPE_MEM_TRAN;
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unsigned long irqflags;
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dev_dbg(chan2dev(chan), "%s: src=%pad, dest=%pad, len=%zd, flags=0x%lx\n",
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__func__, &src, &dest, len, flags);
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@ -798,9 +803,9 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
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dev_dbg(chan2dev(chan), "%s: remaining_size=%zu\n", __func__, remaining_size);
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, irqflags);
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desc = at_xdmac_get_desc(atchan);
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, irqflags);
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if (!desc) {
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dev_err(chan2dev(chan), "can't get descriptor\n");
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if (first)
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@ -886,6 +891,7 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
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int residue;
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u32 cur_nda, mask, value;
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u8 dwidth = 0;
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unsigned long flags;
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ret = dma_cookie_status(chan, cookie, txstate);
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if (ret == DMA_COMPLETE)
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@ -894,7 +900,7 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
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if (!txstate)
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return ret;
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, flags);
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desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc, xfer_node);
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@ -904,8 +910,7 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
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*/
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if (!desc->active_xfer) {
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dma_set_residue(txstate, desc->xfer_size);
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spin_unlock_bh(&atchan->lock);
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return ret;
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goto spin_unlock;
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}
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residue = desc->xfer_size;
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@ -936,14 +941,14 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
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}
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residue += at_xdmac_chan_read(atchan, AT_XDMAC_CUBC) << dwidth;
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spin_unlock_bh(&atchan->lock);
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dma_set_residue(txstate, residue);
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dev_dbg(chan2dev(chan),
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"%s: desc=0x%p, tx_dma_desc.phys=%pad, tx_status=%d, cookie=%d, residue=%d\n",
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__func__, desc, &desc->tx_dma_desc.phys, ret, cookie, residue);
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spin_unlock:
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spin_unlock_irqrestore(&atchan->lock, flags);
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return ret;
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}
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@ -964,8 +969,9 @@ static void at_xdmac_remove_xfer(struct at_xdmac_chan *atchan,
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static void at_xdmac_advance_work(struct at_xdmac_chan *atchan)
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{
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struct at_xdmac_desc *desc;
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unsigned long flags;
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, flags);
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/*
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* If channel is enabled, do nothing, advance_work will be triggered
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@ -980,7 +986,7 @@ static void at_xdmac_advance_work(struct at_xdmac_chan *atchan)
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at_xdmac_start_xfer(atchan, desc);
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}
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, flags);
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}
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static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
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@ -1116,12 +1122,13 @@ static int at_xdmac_device_config(struct dma_chan *chan,
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{
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struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
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int ret;
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unsigned long flags;
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dev_dbg(chan2dev(chan), "%s\n", __func__);
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, flags);
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ret = at_xdmac_set_slave_config(chan, config);
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, flags);
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return ret;
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}
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@ -1130,18 +1137,19 @@ static int at_xdmac_device_pause(struct dma_chan *chan)
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{
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struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
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struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
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unsigned long flags;
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dev_dbg(chan2dev(chan), "%s\n", __func__);
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if (test_and_set_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status))
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return 0;
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, flags);
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at_xdmac_write(atxdmac, AT_XDMAC_GRWS, atchan->mask);
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while (at_xdmac_chan_read(atchan, AT_XDMAC_CC)
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& (AT_XDMAC_CC_WRIP | AT_XDMAC_CC_RDIP))
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cpu_relax();
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, flags);
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return 0;
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}
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@ -1150,18 +1158,19 @@ static int at_xdmac_device_resume(struct dma_chan *chan)
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{
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struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
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struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
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unsigned long flags;
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dev_dbg(chan2dev(chan), "%s\n", __func__);
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, flags);
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if (!at_xdmac_chan_is_paused(atchan)) {
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, flags);
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return 0;
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}
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at_xdmac_write(atxdmac, AT_XDMAC_GRWR, atchan->mask);
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clear_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, flags);
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return 0;
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}
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@ -1171,10 +1180,11 @@ static int at_xdmac_device_terminate_all(struct dma_chan *chan)
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struct at_xdmac_desc *desc, *_desc;
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struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
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struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
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unsigned long flags;
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dev_dbg(chan2dev(chan), "%s\n", __func__);
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, flags);
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at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
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while (at_xdmac_read(atxdmac, AT_XDMAC_GS) & atchan->mask)
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cpu_relax();
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@ -1184,7 +1194,7 @@ static int at_xdmac_device_terminate_all(struct dma_chan *chan)
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at_xdmac_remove_xfer(atchan, desc);
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clear_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status);
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, flags);
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return 0;
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}
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@ -1194,8 +1204,9 @@ static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)
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struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
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struct at_xdmac_desc *desc;
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int i;
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unsigned long flags;
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spin_lock_bh(&atchan->lock);
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spin_lock_irqsave(&atchan->lock, flags);
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if (at_xdmac_chan_is_enabled(atchan)) {
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dev_err(chan2dev(chan),
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@ -1226,7 +1237,7 @@ static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)
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dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
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spin_unlock:
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spin_unlock_bh(&atchan->lock);
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spin_unlock_irqrestore(&atchan->lock, flags);
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return i;
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}
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