diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-14 15:48:26 -1000 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-14 15:48:26 -1000 |
commit | b86a7563ca617aa49dfd6b836da4dd0351fe2acc (patch) | |
tree | 29b6dc87f9a8f9cf2d1aee5e24c4f697240651a0 | |
parent | dc75117fa28af52220cf31ea18493684cf0ffc35 (diff) | |
parent | 88d04643c66052a1cf92a6fd5f92dff0f7757f61 (diff) | |
download | linux-stable-b86a7563ca617aa49dfd6b836da4dd0351fe2acc.tar.gz linux-stable-b86a7563ca617aa49dfd6b836da4dd0351fe2acc.tar.bz2 linux-stable-b86a7563ca617aa49dfd6b836da4dd0351fe2acc.zip |
Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma
Pull dmaengine fixes from Vinod Koul:
"Here are hopefully last set of fixes for 4.1. This time we have:
- fixing pause capability reporting on both dmaengine pause & resume
support by Krzysztof
- locking fix fir at_xdmac by Ludovic
- slave configuration fix for at_xdmac by Ludovic"
* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
dmaengine: Fix choppy sound because of unimplemented resume
dmaengine: at_xdmac: rework slave configuration part
dmaengine: at_xdmac: lock fixes
-rw-r--r-- | drivers/dma/at_xdmac.c | 231 | ||||
-rw-r--r-- | drivers/dma/dmaengine.c | 6 |
2 files changed, 144 insertions, 93 deletions
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 933e4b338459..7992164ea9ec 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -174,6 +174,8 @@ #define AT_XDMAC_MBR_UBC_NDV3 (0x3 << 27) /* Next Descriptor View 3 */ #define AT_XDMAC_MAX_CHAN 0x20 +#define AT_XDMAC_MAX_CSIZE 16 /* 16 data */ +#define AT_XDMAC_MAX_DWIDTH 8 /* 64 bits */ #define AT_XDMAC_DMA_BUSWIDTHS\ (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\ @@ -192,20 +194,17 @@ struct at_xdmac_chan { struct dma_chan chan; void __iomem *ch_regs; u32 mask; /* Channel Mask */ - u32 cfg[2]; /* Channel Configuration Register */ - #define AT_XDMAC_DEV_TO_MEM_CFG 0 /* Predifined dev to mem channel conf */ - #define AT_XDMAC_MEM_TO_DEV_CFG 1 /* Predifined mem to dev channel conf */ + u32 cfg; /* Channel Configuration Register */ u8 perid; /* Peripheral ID */ u8 perif; /* Peripheral Interface */ u8 memif; /* Memory Interface */ - u32 per_src_addr; - u32 per_dst_addr; u32 save_cc; u32 save_cim; u32 save_cnda; u32 save_cndc; unsigned long status; struct tasklet_struct tasklet; + struct dma_slave_config sconfig; spinlock_t lock; @@ -415,8 +414,9 @@ static dma_cookie_t at_xdmac_tx_submit(struct dma_async_tx_descriptor *tx) struct at_xdmac_desc *desc = txd_to_at_desc(tx); struct at_xdmac_chan *atchan = to_at_xdmac_chan(tx->chan); dma_cookie_t cookie; + unsigned long irqflags; - spin_lock_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, irqflags); cookie = dma_cookie_assign(tx); dev_vdbg(chan2dev(tx->chan), "%s: atchan 0x%p, add desc 0x%p to xfers_list\n", @@ -425,7 +425,7 @@ static dma_cookie_t at_xdmac_tx_submit(struct dma_async_tx_descriptor *tx) if (list_is_singular(&atchan->xfers_list)) at_xdmac_start_xfer(atchan, desc); - spin_unlock_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, irqflags); return cookie; } @@ -494,61 +494,94 @@ static struct dma_chan *at_xdmac_xlate(struct of_phandle_args *dma_spec, return chan; } +static int at_xdmac_compute_chan_conf(struct dma_chan *chan, + enum dma_transfer_direction direction) +{ + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan); + int csize, dwidth; + + if (direction == DMA_DEV_TO_MEM) { + atchan->cfg = + AT91_XDMAC_DT_PERID(atchan->perid) + | AT_XDMAC_CC_DAM_INCREMENTED_AM + | AT_XDMAC_CC_SAM_FIXED_AM + | AT_XDMAC_CC_DIF(atchan->memif) + | AT_XDMAC_CC_SIF(atchan->perif) + | AT_XDMAC_CC_SWREQ_HWR_CONNECTED + | AT_XDMAC_CC_DSYNC_PER2MEM + | AT_XDMAC_CC_MBSIZE_SIXTEEN + | AT_XDMAC_CC_TYPE_PER_TRAN; + csize = ffs(atchan->sconfig.src_maxburst) - 1; + if (csize < 0) { + dev_err(chan2dev(chan), "invalid src maxburst value\n"); + return -EINVAL; + } + atchan->cfg |= AT_XDMAC_CC_CSIZE(csize); + dwidth = ffs(atchan->sconfig.src_addr_width) - 1; + if (dwidth < 0) { + dev_err(chan2dev(chan), "invalid src addr width value\n"); + return -EINVAL; + } + atchan->cfg |= AT_XDMAC_CC_DWIDTH(dwidth); + } else if (direction == DMA_MEM_TO_DEV) { + atchan->cfg = + AT91_XDMAC_DT_PERID(atchan->perid) + | AT_XDMAC_CC_DAM_FIXED_AM + | AT_XDMAC_CC_SAM_INCREMENTED_AM + | AT_XDMAC_CC_DIF(atchan->perif) + | AT_XDMAC_CC_SIF(atchan->memif) + | AT_XDMAC_CC_SWREQ_HWR_CONNECTED + | AT_XDMAC_CC_DSYNC_MEM2PER + | AT_XDMAC_CC_MBSIZE_SIXTEEN + | AT_XDMAC_CC_TYPE_PER_TRAN; + csize = ffs(atchan->sconfig.dst_maxburst) - 1; + if (csize < 0) { + dev_err(chan2dev(chan), "invalid src maxburst value\n"); + return -EINVAL; + } + atchan->cfg |= AT_XDMAC_CC_CSIZE(csize); + dwidth = ffs(atchan->sconfig.dst_addr_width) - 1; + if (dwidth < 0) { + dev_err(chan2dev(chan), "invalid dst addr width value\n"); + return -EINVAL; + } + atchan->cfg |= AT_XDMAC_CC_DWIDTH(dwidth); + } + + dev_dbg(chan2dev(chan), "%s: cfg=0x%08x\n", __func__, atchan->cfg); + + return 0; +} + +/* + * Only check that maxburst and addr width values are supported by the + * the controller but not that the configuration is good to perform the + * transfer since we don't know the direction at this stage. + */ +static int at_xdmac_check_slave_config(struct dma_slave_config *sconfig) +{ + if ((sconfig->src_maxburst > AT_XDMAC_MAX_CSIZE) + || (sconfig->dst_maxburst > AT_XDMAC_MAX_CSIZE)) + return -EINVAL; + + if ((sconfig->src_addr_width > AT_XDMAC_MAX_DWIDTH) + || (sconfig->dst_addr_width > AT_XDMAC_MAX_DWIDTH)) + return -EINVAL; + + return 0; +} + static int at_xdmac_set_slave_config(struct dma_chan *chan, struct dma_slave_config *sconfig) { struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan); - u8 dwidth; - int csize; - atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG] = - AT91_XDMAC_DT_PERID(atchan->perid) - | AT_XDMAC_CC_DAM_INCREMENTED_AM - | AT_XDMAC_CC_SAM_FIXED_AM - | AT_XDMAC_CC_DIF(atchan->memif) - | AT_XDMAC_CC_SIF(atchan->perif) - | AT_XDMAC_CC_SWREQ_HWR_CONNECTED - | AT_XDMAC_CC_DSYNC_PER2MEM - | AT_XDMAC_CC_MBSIZE_SIXTEEN - | AT_XDMAC_CC_TYPE_PER_TRAN; - csize = at_xdmac_csize(sconfig->src_maxburst); - if (csize < 0) { - dev_err(chan2dev(chan), "invalid src maxburst value\n"); + if (at_xdmac_check_slave_config(sconfig)) { + dev_err(chan2dev(chan), "invalid slave configuration\n"); return -EINVAL; } - atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG] |= AT_XDMAC_CC_CSIZE(csize); - dwidth = ffs(sconfig->src_addr_width) - 1; - atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG] |= AT_XDMAC_CC_DWIDTH(dwidth); - - - atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG] = - AT91_XDMAC_DT_PERID(atchan->perid) - | AT_XDMAC_CC_DAM_FIXED_AM - | AT_XDMAC_CC_SAM_INCREMENTED_AM - | AT_XDMAC_CC_DIF(atchan->perif) - | AT_XDMAC_CC_SIF(atchan->memif) - | AT_XDMAC_CC_SWREQ_HWR_CONNECTED - | AT_XDMAC_CC_DSYNC_MEM2PER - | AT_XDMAC_CC_MBSIZE_SIXTEEN - | AT_XDMAC_CC_TYPE_PER_TRAN; - csize = at_xdmac_csize(sconfig->dst_maxburst); - if (csize < 0) { - dev_err(chan2dev(chan), "invalid src maxburst value\n"); - return -EINVAL; - } - atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG] |= AT_XDMAC_CC_CSIZE(csize); - dwidth = ffs(sconfig->dst_addr_width) - 1; - atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG] |= AT_XDMAC_CC_DWIDTH(dwidth); - - /* Src and dst addr are needed to configure the link list descriptor. */ - atchan->per_src_addr = sconfig->src_addr; - atchan->per_dst_addr = sconfig->dst_addr; - dev_dbg(chan2dev(chan), - "%s: cfg[dev2mem]=0x%08x, cfg[mem2dev]=0x%08x, per_src_addr=0x%08x, per_dst_addr=0x%08x\n", - __func__, atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG], - atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG], - atchan->per_src_addr, atchan->per_dst_addr); + memcpy(&atchan->sconfig, sconfig, sizeof(atchan->sconfig)); return 0; } @@ -563,6 +596,8 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, struct scatterlist *sg; int i; unsigned int xfer_size = 0; + unsigned long irqflags; + struct dma_async_tx_descriptor *ret = NULL; if (!sgl) return NULL; @@ -578,7 +613,10 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, flags); /* Protect dma_sconfig field that can be modified by set_slave_conf. */ - spin_lock_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, irqflags); + + if (at_xdmac_compute_chan_conf(chan, direction)) + goto spin_unlock; /* Prepare descriptors. */ for_each_sg(sgl, sg, sg_len, i) { @@ -589,8 +627,7 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, mem = sg_dma_address(sg); if (unlikely(!len)) { dev_err(chan2dev(chan), "sg data length is zero\n"); - spin_unlock_bh(&atchan->lock); - return NULL; + goto spin_unlock; } dev_dbg(chan2dev(chan), "%s: * sg%d len=%u, mem=0x%08x\n", __func__, i, len, mem); @@ -600,20 +637,18 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, dev_err(chan2dev(chan), "can't get descriptor\n"); if (first) list_splice_init(&first->descs_list, &atchan->free_descs_list); - spin_unlock_bh(&atchan->lock); - return NULL; + goto spin_unlock; } /* Linked list descriptor setup. */ if (direction == DMA_DEV_TO_MEM) { - desc->lld.mbr_sa = atchan->per_src_addr; + desc->lld.mbr_sa = atchan->sconfig.src_addr; desc->lld.mbr_da = mem; - desc->lld.mbr_cfg = atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG]; } else { desc->lld.mbr_sa = mem; - desc->lld.mbr_da = atchan->per_dst_addr; - desc->lld.mbr_cfg = atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG]; + desc->lld.mbr_da = atchan->sconfig.dst_addr; } + desc->lld.mbr_cfg = atchan->cfg; dwidth = at_xdmac_get_dwidth(desc->lld.mbr_cfg); fixed_dwidth = IS_ALIGNED(len, 1 << dwidth) ? at_xdmac_get_dwidth(desc->lld.mbr_cfg) @@ -645,13 +680,15 @@ at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, xfer_size += len; } - spin_unlock_bh(&atchan->lock); first->tx_dma_desc.flags = flags; first->xfer_size = xfer_size; first->direction = direction; + ret = &first->tx_dma_desc; - return &first->tx_dma_desc; +spin_unlock: + spin_unlock_irqrestore(&atchan->lock, irqflags); + return ret; } static struct dma_async_tx_descriptor * @@ -664,6 +701,7 @@ at_xdmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, struct at_xdmac_desc *first = NULL, *prev = NULL; unsigned int periods = buf_len / period_len; int i; + unsigned long irqflags; dev_dbg(chan2dev(chan), "%s: buf_addr=%pad, buf_len=%zd, period_len=%zd, dir=%s, flags=0x%lx\n", __func__, &buf_addr, buf_len, period_len, @@ -679,32 +717,34 @@ at_xdmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, return NULL; } + if (at_xdmac_compute_chan_conf(chan, direction)) + return NULL; + for (i = 0; i < periods; i++) { struct at_xdmac_desc *desc = NULL; - spin_lock_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, irqflags); desc = at_xdmac_get_desc(atchan); if (!desc) { dev_err(chan2dev(chan), "can't get descriptor\n"); if (first) list_splice_init(&first->descs_list, &atchan->free_descs_list); - spin_unlock_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, irqflags); return NULL; } - spin_unlock_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, irqflags); dev_dbg(chan2dev(chan), "%s: desc=0x%p, tx_dma_desc.phys=%pad\n", __func__, desc, &desc->tx_dma_desc.phys); if (direction == DMA_DEV_TO_MEM) { - desc->lld.mbr_sa = atchan->per_src_addr; + desc->lld.mbr_sa = atchan->sconfig.src_addr; desc->lld.mbr_da = buf_addr + i * period_len; - desc->lld.mbr_cfg = atchan->cfg[AT_XDMAC_DEV_TO_MEM_CFG]; } else { desc->lld.mbr_sa = buf_addr + i * period_len; - desc->lld.mbr_da = atchan->per_dst_addr; - desc->lld.mbr_cfg = atchan->cfg[AT_XDMAC_MEM_TO_DEV_CFG]; + desc->lld.mbr_da = atchan->sconfig.dst_addr; } + desc->lld.mbr_cfg = atchan->cfg; desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV1 | AT_XDMAC_MBR_UBC_NDEN | AT_XDMAC_MBR_UBC_NSEN @@ -766,6 +806,7 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, | AT_XDMAC_CC_SIF(0) | AT_XDMAC_CC_MBSIZE_SIXTEEN | AT_XDMAC_CC_TYPE_MEM_TRAN; + unsigned long irqflags; dev_dbg(chan2dev(chan), "%s: src=%pad, dest=%pad, len=%zd, flags=0x%lx\n", __func__, &src, &dest, len, flags); @@ -798,9 +839,9 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, dev_dbg(chan2dev(chan), "%s: remaining_size=%zu\n", __func__, remaining_size); - spin_lock_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, irqflags); desc = at_xdmac_get_desc(atchan); - spin_unlock_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, irqflags); if (!desc) { dev_err(chan2dev(chan), "can't get descriptor\n"); if (first) @@ -886,6 +927,7 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, int residue; u32 cur_nda, mask, value; u8 dwidth = 0; + unsigned long flags; ret = dma_cookie_status(chan, cookie, txstate); if (ret == DMA_COMPLETE) @@ -894,7 +936,7 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, if (!txstate) return ret; - spin_lock_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, flags); desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc, xfer_node); @@ -904,8 +946,7 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, */ if (!desc->active_xfer) { dma_set_residue(txstate, desc->xfer_size); - spin_unlock_bh(&atchan->lock); - return ret; + goto spin_unlock; } residue = desc->xfer_size; @@ -936,14 +977,14 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, } residue += at_xdmac_chan_read(atchan, AT_XDMAC_CUBC) << dwidth; - spin_unlock_bh(&atchan->lock); - dma_set_residue(txstate, residue); dev_dbg(chan2dev(chan), "%s: desc=0x%p, tx_dma_desc.phys=%pad, tx_status=%d, cookie=%d, residue=%d\n", __func__, desc, &desc->tx_dma_desc.phys, ret, cookie, residue); +spin_unlock: + spin_unlock_irqrestore(&atchan->lock, flags); return ret; } @@ -964,8 +1005,9 @@ static void at_xdmac_remove_xfer(struct at_xdmac_chan *atchan, static void at_xdmac_advance_work(struct at_xdmac_chan *atchan) { struct at_xdmac_desc *desc; + unsigned long flags; - spin_lock_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, flags); /* * If channel is enabled, do nothing, advance_work will be triggered @@ -980,7 +1022,7 @@ static void at_xdmac_advance_work(struct at_xdmac_chan *atchan) at_xdmac_start_xfer(atchan, desc); } - spin_unlock_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, flags); } static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan) @@ -1116,12 +1158,13 @@ static int at_xdmac_device_config(struct dma_chan *chan, { struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan); int ret; + unsigned long flags; dev_dbg(chan2dev(chan), "%s\n", __func__); - spin_lock_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, flags); ret = at_xdmac_set_slave_config(chan, config); - spin_unlock_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, flags); return ret; } @@ -1130,18 +1173,19 @@ static int at_xdmac_device_pause(struct dma_chan *chan) { struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan); struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device); + unsigned long flags; dev_dbg(chan2dev(chan), "%s\n", __func__); if (test_and_set_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status)) return 0; - spin_lock_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, flags); at_xdmac_write(atxdmac, AT_XDMAC_GRWS, atchan->mask); while (at_xdmac_chan_read(atchan, AT_XDMAC_CC) & (AT_XDMAC_CC_WRIP | AT_XDMAC_CC_RDIP)) cpu_relax(); - spin_unlock_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, flags); return 0; } @@ -1150,18 +1194,19 @@ static int at_xdmac_device_resume(struct dma_chan *chan) { struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan); struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device); + unsigned long flags; dev_dbg(chan2dev(chan), "%s\n", __func__); - spin_lock_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, flags); if (!at_xdmac_chan_is_paused(atchan)) { - spin_unlock_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, flags); return 0; } at_xdmac_write(atxdmac, AT_XDMAC_GRWR, atchan->mask); clear_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status); - spin_unlock_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, flags); return 0; } @@ -1171,10 +1216,11 @@ static int at_xdmac_device_terminate_all(struct dma_chan *chan) struct at_xdmac_desc *desc, *_desc; struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan); struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device); + unsigned long flags; dev_dbg(chan2dev(chan), "%s\n", __func__); - spin_lock_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, flags); at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask); while (at_xdmac_read(atxdmac, AT_XDMAC_GS) & atchan->mask) cpu_relax(); @@ -1184,7 +1230,7 @@ static int at_xdmac_device_terminate_all(struct dma_chan *chan) at_xdmac_remove_xfer(atchan, desc); clear_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status); - spin_unlock_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, flags); return 0; } @@ -1194,8 +1240,9 @@ 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_bh(&atchan->lock); + spin_lock_irqsave(&atchan->lock, flags); if (at_xdmac_chan_is_enabled(atchan)) { dev_err(chan2dev(chan), @@ -1226,7 +1273,7 @@ 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_bh(&atchan->lock); + spin_unlock_irqrestore(&atchan->lock, flags); return i; } diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 2890d744bb1b..3ddfd1f6c23c 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -487,7 +487,11 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps) caps->directions = device->directions; caps->residue_granularity = device->residue_granularity; - caps->cmd_pause = !!device->device_pause; + /* + * Some devices implement only pause (e.g. to get residuum) but no + * resume. However cmd_pause is advertised as pause AND resume. + */ + caps->cmd_pause = !!(device->device_pause && device->device_resume); caps->cmd_terminate = !!device->device_terminate_all; return 0; |