Subject: [PATCH v7 0/6] dmaengine: xilinx_dma: Bug fixes

This patch series fixes below bugs in DMA and VDMA IP's
---> Added channel idle checks in the driver before submitting the buffer descriptor to h/w.
---> Fixes bug in Multi frame sotres handling in VDMA
---> Fixes issues w.r.to multi frame descriptors submit with AXI DMA S2MM(recv) Side.
---> Fixed kernel doc warnings in the driver.
---> Fixed checkpatch errors in the driver.

Kedareswara rao Appana (6):
dmaengine: xilinx_dma: Check for channel idle state before submitting
dma descriptor
dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in
vdma
dmaengine: xilinx_dma: Fix race condition in the driver for multiple
descriptor scenario
dmaengine: xilinx_dma: Fix kernel doc warnings
dmaengine: xilinx_dma: fix style issues from checkpatch
dmaengine: xilinx_dma: Differentiate probe based on the ip type

drivers/dma/xilinx/xilinx_dma.c | 283 ++++++++++++++++++++++------------------
1 file changed, 157 insertions(+), 126 deletions(-)

--
2.7.4


Subject: [PATCH v7 1/6] dmaengine: xilinx_dma: Check for channel idle state before submitting dma descriptor

Add variable for checking channel idle state to ensure that dma
descriptor is not submitted when dmaengine is in progress.

This will avoid the polling for a bit in the status register to know
dma state in the driver hot path.

Reviewed-by: Jose Abreu <[email protected]>
Signed-off-by: Kedareswara rao Appana <[email protected]>
---
Changes for v7:
---> None.
Changes for v6:
---> Updated commit message as suggested by Vinod.
---> Added Channel idle variable description in the driver
as suggested by Vinod.
Changes for v5:
---> None.
Changes for v4:
---> None.
Changes for v3:
---> None.
Changes for v2:
---> Add idle check in the reset as suggested by Jose Abreu
---> Removed xilinx_dma_is_running/xilinx_dma_is_idle checks
in the driver and used common idle checks across the driver
as suggested by Laurent Pinchart.

drivers/dma/xilinx/xilinx_dma.c | 60 +++++++++++++++--------------------------
1 file changed, 22 insertions(+), 38 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 5eef133..c246563 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -321,6 +321,7 @@ struct xilinx_dma_tx_descriptor {
* @cyclic: Check for cyclic transfers.
* @genlock: Support genlock mode
* @err: Channel has errors
+ * @idle: Check for channel idle
* @tasklet: Cleanup work after irq
* @config: Device configuration info
* @flush_on_fsync: Flush on Frame sync
@@ -352,6 +353,7 @@ struct xilinx_dma_chan {
bool cyclic;
bool genlock;
bool err;
+ bool idle;
struct tasklet_struct tasklet;
struct xilinx_vdma_config config;
bool flush_on_fsync;
@@ -936,32 +938,6 @@ static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan,
}

/**
- * xilinx_dma_is_running - Check if DMA channel is running
- * @chan: Driver specific DMA channel
- *
- * Return: '1' if running, '0' if not.
- */
-static bool xilinx_dma_is_running(struct xilinx_dma_chan *chan)
-{
- return !(dma_ctrl_read(chan, XILINX_DMA_REG_DMASR) &
- XILINX_DMA_DMASR_HALTED) &&
- (dma_ctrl_read(chan, XILINX_DMA_REG_DMACR) &
- XILINX_DMA_DMACR_RUNSTOP);
-}
-
-/**
- * xilinx_dma_is_idle - Check if DMA channel is idle
- * @chan: Driver specific DMA channel
- *
- * Return: '1' if idle, '0' if not.
- */
-static bool xilinx_dma_is_idle(struct xilinx_dma_chan *chan)
-{
- return dma_ctrl_read(chan, XILINX_DMA_REG_DMASR) &
- XILINX_DMA_DMASR_IDLE;
-}
-
-/**
* xilinx_dma_stop_transfer - Halt DMA channel
* @chan: Driver specific DMA channel
*/
@@ -1029,6 +1005,9 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
if (chan->err)
return;

+ if (!chan->idle)
+ return;
+
if (list_empty(&chan->pending_list))
return;

@@ -1040,13 +1019,6 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
tail_segment = list_last_entry(&tail_desc->segments,
struct xilinx_vdma_tx_segment, node);

- /* If it is SG mode and hardware is busy, cannot submit */
- if (chan->has_sg && xilinx_dma_is_running(chan) &&
- !xilinx_dma_is_idle(chan)) {
- dev_dbg(chan->dev, "DMA controller still busy\n");
- return;
- }
-
/*
* If hardware is idle, then all descriptors on the running lists are
* done, start new transfers
@@ -1143,6 +1115,8 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
list_splice_tail_init(&chan->pending_list, &chan->active_list);
chan->desc_pendingcount = 0;
}
+
+ chan->idle = false;
}

/**
@@ -1158,6 +1132,9 @@ static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
if (chan->err)
return;

+ if (!chan->idle)
+ return;
+
if (list_empty(&chan->pending_list))
return;

@@ -1203,6 +1180,7 @@ static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)

list_splice_tail_init(&chan->pending_list, &chan->active_list);
chan->desc_pendingcount = 0;
+ chan->idle = false;
}

/**
@@ -1221,12 +1199,8 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
if (list_empty(&chan->pending_list))
return;

- /* If it is SG mode and hardware is busy, cannot submit */
- if (chan->has_sg && xilinx_dma_is_running(chan) &&
- !xilinx_dma_is_idle(chan)) {
- dev_dbg(chan->dev, "DMA controller still busy\n");
+ if (!chan->idle)
return;
- }

head_desc = list_first_entry(&chan->pending_list,
struct xilinx_dma_tx_descriptor, node);
@@ -1324,6 +1298,7 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)

list_splice_tail_init(&chan->pending_list, &chan->active_list);
chan->desc_pendingcount = 0;
+ chan->idle = false;
}

/**
@@ -1388,6 +1363,7 @@ static int xilinx_dma_reset(struct xilinx_dma_chan *chan)
}

chan->err = false;
+ chan->idle = true;

return err;
}
@@ -1469,6 +1445,7 @@ static irqreturn_t xilinx_dma_irq_handler(int irq, void *data)
if (status & XILINX_DMA_DMASR_FRM_CNT_IRQ) {
spin_lock(&chan->lock);
xilinx_dma_complete_descriptor(chan);
+ chan->idle = true;
chan->start_transfer(chan);
spin_unlock(&chan->lock);
}
@@ -2029,6 +2006,7 @@ static int xilinx_dma_terminate_all(struct dma_chan *dchan)

/* Remove and free all of the descriptors in the lists */
xilinx_dma_free_descriptors(chan);
+ chan->idle = true;

if (chan->cyclic) {
reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
@@ -2344,6 +2322,12 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
chan->has_sg = xdev->has_sg;
chan->desc_pendingcount = 0x0;
chan->ext_addr = xdev->ext_addr;
+ /* This variable enusres that descripotrs are not
+ * Submited when dma engine is in progress. This variable is
+ * Added to avoid pollling for a bit in the status register to
+ * Know dma state in the driver hot path.
+ */
+ chan->idle = true;

spin_lock_init(&chan->lock);
INIT_LIST_HEAD(&chan->pending_list);
--
2.7.4

Subject: [PATCH v7 3/6] dmaengine: xilinx_dma: Fix race condition in the driver for multiple descriptor scenario

As per axi dmaengine spec the software must not move the tail pointer
to a location that has not been updated (next descriptor field of the
h/w descriptor should always point to a valid address).

When user submits multiple descriptors on the recv side, with the
current driver flow the last buffer descriptor next descriptor field
points to a invalid location, resulting the invalid data or errors from the
axidma dmaengine.

This patch fixes this issue by creating a buffer descritpor chain during
channel allocation itself and use those buffer descriptors for the
subsequent dma operations.

Signed-off-by: Kedareswara rao Appana <[email protected]>
---
Changes for v7:
---> None.
Changes for v6:
---> Updated Commit message as suggested by Vinod.
Changes for v5:
---> None.
Changes for v4:
---> None.
Changes for v3:
---> None.
Changes for v2:
---> None.

drivers/dma/xilinx/xilinx_dma.c | 135 +++++++++++++++++++++++++---------------
1 file changed, 84 insertions(+), 51 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 9063ca0..ab01306 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -165,6 +165,7 @@
#define XILINX_DMA_BD_SOP BIT(27)
#define XILINX_DMA_BD_EOP BIT(26)
#define XILINX_DMA_COALESCE_MAX 255
+#define XILINX_DMA_NUM_DESCS 255
#define XILINX_DMA_NUM_APP_WORDS 5

/* Multi-Channel DMA Descriptor offsets*/
@@ -312,6 +313,7 @@ struct xilinx_dma_tx_descriptor {
* @pending_list: Descriptors waiting
* @active_list: Descriptors ready to submit
* @done_list: Complete descriptors
+ * @free_seg_list: Free descriptors
* @common: DMA common channel
* @desc_pool: Descriptors pool
* @dev: The dma device
@@ -332,7 +334,9 @@ struct xilinx_dma_tx_descriptor {
* @desc_submitcount: Descriptor h/w submitted count
* @residue: Residue for AXI DMA
* @seg_v: Statically allocated segments base
+ * @seg_p: Physical allocated segments base
* @cyclic_seg_v: Statically allocated segment base for cyclic transfers
+ * @cyclic_seg_p: Physical allocated segments base for cyclic dma
* @start_transfer: Differentiate b/w DMA IP's transfer
* @stop_transfer: Differentiate b/w DMA IP's quiesce
*/
@@ -344,6 +348,7 @@ struct xilinx_dma_chan {
struct list_head pending_list;
struct list_head active_list;
struct list_head done_list;
+ struct list_head free_seg_list;
struct dma_chan common;
struct dma_pool *desc_pool;
struct device *dev;
@@ -364,7 +369,9 @@ struct xilinx_dma_chan {
u32 desc_submitcount;
u32 residue;
struct xilinx_axidma_tx_segment *seg_v;
+ dma_addr_t seg_p;
struct xilinx_axidma_tx_segment *cyclic_seg_v;
+ dma_addr_t cyclic_seg_p;
void (*start_transfer)(struct xilinx_dma_chan *chan);
int (*stop_transfer)(struct xilinx_dma_chan *chan);
u16 tdest;
@@ -584,18 +591,32 @@ xilinx_cdma_alloc_tx_segment(struct xilinx_dma_chan *chan)
static struct xilinx_axidma_tx_segment *
xilinx_axidma_alloc_tx_segment(struct xilinx_dma_chan *chan)
{
- struct xilinx_axidma_tx_segment *segment;
- dma_addr_t phys;
-
- segment = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &phys);
- if (!segment)
- return NULL;
+ struct xilinx_axidma_tx_segment *segment = NULL;
+ unsigned long flags;

- segment->phys = phys;
+ spin_lock_irqsave(&chan->lock, flags);
+ if (!list_empty(&chan->free_seg_list)) {
+ segment = list_first_entry(&chan->free_seg_list,
+ struct xilinx_axidma_tx_segment,
+ node);
+ list_del(&segment->node);
+ }
+ spin_unlock_irqrestore(&chan->lock, flags);

return segment;
}

+static void xilinx_dma_clean_hw_desc(struct xilinx_axidma_desc_hw *hw)
+{
+ u32 next_desc = hw->next_desc;
+ u32 next_desc_msb = hw->next_desc_msb;
+
+ memset(hw, 0, sizeof(struct xilinx_axidma_desc_hw));
+
+ hw->next_desc = next_desc;
+ hw->next_desc_msb = next_desc_msb;
+}
+
/**
* xilinx_dma_free_tx_segment - Free transaction segment
* @chan: Driver specific DMA channel
@@ -604,7 +625,9 @@ xilinx_axidma_alloc_tx_segment(struct xilinx_dma_chan *chan)
static void xilinx_dma_free_tx_segment(struct xilinx_dma_chan *chan,
struct xilinx_axidma_tx_segment *segment)
{
- dma_pool_free(chan->desc_pool, segment, segment->phys);
+ xilinx_dma_clean_hw_desc(&segment->hw);
+
+ list_add_tail(&segment->node, &chan->free_seg_list);
}

/**
@@ -729,16 +752,26 @@ static void xilinx_dma_free_descriptors(struct xilinx_dma_chan *chan)
static void xilinx_dma_free_chan_resources(struct dma_chan *dchan)
{
struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
+ unsigned long flags;

dev_dbg(chan->dev, "Free all channel resources.\n");

xilinx_dma_free_descriptors(chan);
+
if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
- xilinx_dma_free_tx_segment(chan, chan->cyclic_seg_v);
- xilinx_dma_free_tx_segment(chan, chan->seg_v);
+ spin_lock_irqsave(&chan->lock, flags);
+ INIT_LIST_HEAD(&chan->free_seg_list);
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ /* Free Memory that is allocated for cyclic DMA Mode */
+ dma_free_coherent(chan->dev, sizeof(*chan->cyclic_seg_v),
+ chan->cyclic_seg_v, chan->cyclic_seg_p);
+ }
+
+ if (chan->xdev->dma_config->dmatype != XDMA_TYPE_AXIDMA) {
+ dma_pool_destroy(chan->desc_pool);
+ chan->desc_pool = NULL;
}
- dma_pool_destroy(chan->desc_pool);
- chan->desc_pool = NULL;
}

/**
@@ -821,6 +854,7 @@ static void xilinx_dma_do_tasklet(unsigned long data)
static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
{
struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
+ int i;

/* Has this channel already been allocated? */
if (chan->desc_pool)
@@ -831,11 +865,30 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
* for meeting Xilinx VDMA specification requirement.
*/
if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
- chan->desc_pool = dma_pool_create("xilinx_dma_desc_pool",
- chan->dev,
- sizeof(struct xilinx_axidma_tx_segment),
- __alignof__(struct xilinx_axidma_tx_segment),
- 0);
+ /* Allocate the buffer descriptors. */
+ chan->seg_v = dma_zalloc_coherent(chan->dev,
+ sizeof(*chan->seg_v) *
+ XILINX_DMA_NUM_DESCS,
+ &chan->seg_p, GFP_KERNEL);
+ if (!chan->seg_v) {
+ dev_err(chan->dev,
+ "unable to allocate channel %d descriptors\n",
+ chan->id);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < XILINX_DMA_NUM_DESCS; i++) {
+ chan->seg_v[i].hw.next_desc =
+ lower_32_bits(chan->seg_p + sizeof(*chan->seg_v) *
+ ((i + 1) % XILINX_DMA_NUM_DESCS));
+ chan->seg_v[i].hw.next_desc_msb =
+ upper_32_bits(chan->seg_p + sizeof(*chan->seg_v) *
+ ((i + 1) % XILINX_DMA_NUM_DESCS));
+ chan->seg_v[i].phys = chan->seg_p +
+ sizeof(*chan->seg_v) * i;
+ list_add_tail(&chan->seg_v[i].node,
+ &chan->free_seg_list);
+ }
} else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
chan->desc_pool = dma_pool_create("xilinx_cdma_desc_pool",
chan->dev,
@@ -850,7 +903,8 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
0);
}

- if (!chan->desc_pool) {
+ if (!chan->desc_pool &&
+ (chan->xdev->dma_config->dmatype != XDMA_TYPE_AXIDMA)) {
dev_err(chan->dev,
"unable to allocate channel %d descriptor pool\n",
chan->id);
@@ -859,22 +913,20 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)

if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
/*
- * For AXI DMA case after submitting a pending_list, keep
- * an extra segment allocated so that the "next descriptor"
- * pointer on the tail descriptor always points to a
- * valid descriptor, even when paused after reaching taildesc.
- * This way, it is possible to issue additional
- * transfers without halting and restarting the channel.
- */
- chan->seg_v = xilinx_axidma_alloc_tx_segment(chan);
-
- /*
* For cyclic DMA mode we need to program the tail Descriptor
* register with a value which is not a part of the BD chain
* so allocating a desc segment during channel allocation for
* programming tail descriptor.
*/
- chan->cyclic_seg_v = xilinx_axidma_alloc_tx_segment(chan);
+ chan->cyclic_seg_v = dma_zalloc_coherent(chan->dev,
+ sizeof(*chan->cyclic_seg_v),
+ &chan->cyclic_seg_p, GFP_KERNEL);
+ if (!chan->cyclic_seg_v) {
+ dev_err(chan->dev,
+ "unable to allocate desc segment for cyclic DMA\n");
+ return -ENOMEM;
+ }
+ chan->cyclic_seg_v->phys = chan->cyclic_seg_p;
}

dma_cookie_init(dchan);
@@ -1184,7 +1236,7 @@ static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
{
struct xilinx_dma_tx_descriptor *head_desc, *tail_desc;
- struct xilinx_axidma_tx_segment *tail_segment, *old_head, *new_head;
+ struct xilinx_axidma_tx_segment *tail_segment;
u32 reg;

if (chan->err)
@@ -1203,21 +1255,6 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
tail_segment = list_last_entry(&tail_desc->segments,
struct xilinx_axidma_tx_segment, node);

- if (chan->has_sg && !chan->xdev->mcdma) {
- old_head = list_first_entry(&head_desc->segments,
- struct xilinx_axidma_tx_segment, node);
- new_head = chan->seg_v;
- /* Copy Buffer Descriptor fields. */
- new_head->hw = old_head->hw;
-
- /* Swap and save new reserve */
- list_replace_init(&old_head->node, &new_head->node);
- chan->seg_v = old_head;
-
- tail_segment->hw.next_desc = chan->seg_v->phys;
- head_desc->async_tx.phys = new_head->phys;
- }
-
reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);

if (chan->desc_pendingcount <= XILINX_DMA_COALESCE_MAX) {
@@ -1705,7 +1742,7 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
{
struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
struct xilinx_dma_tx_descriptor *desc;
- struct xilinx_axidma_tx_segment *segment = NULL, *prev = NULL;
+ struct xilinx_axidma_tx_segment *segment = NULL;
u32 *app_w = (u32 *)context;
struct scatterlist *sg;
size_t copy;
@@ -1756,10 +1793,6 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
XILINX_DMA_NUM_APP_WORDS);
}

- if (prev)
- prev->hw.next_desc = segment->phys;
-
- prev = segment;
sg_used += copy;

/*
@@ -1773,7 +1806,6 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
segment = list_first_entry(&desc->segments,
struct xilinx_axidma_tx_segment, node);
desc->async_tx.phys = segment->phys;
- prev->hw.next_desc = segment->phys;

/* For the last DMA_MEM_TO_DEV transfer, set EOP */
if (chan->direction == DMA_MEM_TO_DEV) {
@@ -2328,6 +2360,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
INIT_LIST_HEAD(&chan->pending_list);
INIT_LIST_HEAD(&chan->done_list);
INIT_LIST_HEAD(&chan->active_list);
+ INIT_LIST_HEAD(&chan->free_seg_list);

/* Retrieve the channel properties from the device tree */
has_dre = of_property_read_bool(node, "xlnx,include-dre");
--
2.7.4

Subject: [PATCH v7 4/6] dmaengine: xilinx_dma: Fix kernel doc warnings

This patch fixes the kernel doc warnings
in the driver.

Signed-off-by: Kedareswara rao Appana <[email protected]>
---
Changes for v7:
--> New patch.

drivers/dma/xilinx/xilinx_dma.c | 37 ++++++++++++++++++++++++-------------
1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index ab01306..eaa93fe 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -214,8 +214,8 @@ struct xilinx_vdma_desc_hw {
* @next_desc_msb: MSB of Next Descriptor Pointer @0x04
* @buf_addr: Buffer address @0x08
* @buf_addr_msb: MSB of Buffer address @0x0C
- * @pad1: Reserved @0x10
- * @pad2: Reserved @0x14
+ * @mcdma_control: Control field for mcdma @0x10
+ * @vsize_stride: Vsize and Stride field for mcdma @0x14
* @control: Control field @0x18
* @status: Status field @0x1C
* @app: APP Fields @0x20 - 0x30
@@ -235,11 +235,11 @@ struct xilinx_axidma_desc_hw {
/**
* struct xilinx_cdma_desc_hw - Hardware Descriptor
* @next_desc: Next Descriptor Pointer @0x00
- * @next_descmsb: Next Descriptor Pointer MSB @0x04
+ * @next_desc_msb: Next Descriptor Pointer MSB @0x04
* @src_addr: Source address @0x08
- * @src_addrmsb: Source address MSB @0x0C
+ * @src_addr_msb: Source address MSB @0x0C
* @dest_addr: Destination address @0x10
- * @dest_addrmsb: Destination address MSB @0x14
+ * @dest_addr_msb: Destination address MSB @0x14
* @control: Control field @0x18
* @status: Status field @0x1C
*/
@@ -339,6 +339,7 @@ struct xilinx_dma_tx_descriptor {
* @cyclic_seg_p: Physical allocated segments base for cyclic dma
* @start_transfer: Differentiate b/w DMA IP's transfer
* @stop_transfer: Differentiate b/w DMA IP's quiesce
+ * @tdest: TDEST value for mcdma
*/
struct xilinx_dma_chan {
struct xilinx_dma_device *xdev;
@@ -378,11 +379,11 @@ struct xilinx_dma_chan {
};

/**
- * enum xdma_ip_type: DMA IP type.
+ * enum xdma_ip_type - DMA IP type.
*
- * XDMA_TYPE_AXIDMA: Axi dma ip.
- * XDMA_TYPE_CDMA: Axi cdma ip.
- * XDMA_TYPE_VDMA: Axi vdma ip.
+ * @XDMA_TYPE_AXIDMA: Axi dma ip.
+ * @XDMA_TYPE_CDMA: Axi cdma ip.
+ * @XDMA_TYPE_VDMA: Axi vdma ip.
*
*/
enum xdma_ip_type {
@@ -994,6 +995,8 @@ static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan,
/**
* xilinx_dma_stop_transfer - Halt DMA channel
* @chan: Driver specific DMA channel
+ *
+ * Return: '0' on success and failure value on error
*/
static int xilinx_dma_stop_transfer(struct xilinx_dma_chan *chan)
{
@@ -1010,6 +1013,8 @@ static int xilinx_dma_stop_transfer(struct xilinx_dma_chan *chan)
/**
* xilinx_cdma_stop_transfer - Wait for the current transfer to complete
* @chan: Driver specific DMA channel
+ *
+ * Return: '0' on success and failure value on error
*/
static int xilinx_cdma_stop_transfer(struct xilinx_dma_chan *chan)
{
@@ -1825,11 +1830,14 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(

/**
* xilinx_dma_prep_dma_cyclic - prepare descriptors for a DMA_SLAVE transaction
- * @chan: DMA channel
- * @sgl: scatterlist to transfer to/from
- * @sg_len: number of entries in @scatterlist
+ * @dchan: DMA channel
+ * @buf_addr: Physical address of the buffer
+ * @buf_len: Total length of the cyclic buffers
+ * @period_len: length of individual cyclic buffer
* @direction: DMA direction
* @flags: transfer ack flags
+ *
+ * Return: Async transaction descriptor on success and NULL on failure
*/
static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic(
struct dma_chan *dchan, dma_addr_t buf_addr, size_t buf_len,
@@ -2013,7 +2021,9 @@ xilinx_dma_prep_interleaved(struct dma_chan *dchan,

/**
* xilinx_dma_terminate_all - Halt the channel and free descriptors
- * @chan: Driver specific DMA Channel pointer
+ * @dchan: Driver specific DMA Channel pointer
+ *
+ * Return: '0' always.
*/
static int xilinx_dma_terminate_all(struct dma_chan *dchan)
{
@@ -2328,6 +2338,7 @@ static void xdma_disable_allclks(struct xilinx_dma_device *xdev)
*
* @xdev: Driver specific device structure
* @node: Device node
+ * @chan_id: DMA Channel id
*
* Return: '0' on success and failure value on error
*/
--
2.7.4

Subject: [PATCH v7 6/6] dmaengine: xilinx_dma: Differentiate probe based on the ip type

This patch updates the probe banner info based on the ip probed.

Signed-off-by: Kedareswara rao Appana <[email protected]>
---
Changes for v7:
--> New patch.

drivers/dma/xilinx/xilinx_dma.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index b09a8ef..52e2f18 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -2680,7 +2680,12 @@ static int xilinx_dma_probe(struct platform_device *pdev)
goto error;
}

- dev_info(&pdev->dev, "Xilinx AXI VDMA Engine Driver Probed!!\n");
+ if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
+ dev_info(&pdev->dev, "Xilinx AXI DMA Engine Driver Probed!!\n");
+ else if (xdev->dma_config->dmatype == XDMA_TYPE_CDMA)
+ dev_info(&pdev->dev, "Xilinx AXI CDMA Engine Driver Probed!!\n");
+ else
+ dev_info(&pdev->dev, "Xilinx AXI VDMA Engine Driver Probed!!\n");

return 0;

--
2.7.4

Subject: [PATCH v7 5/6] dmaengine: xilinx_dma: fix style issues from checkpatch

This patch fixes below.
ERROR: open brace '{' following function definitions go on the next line
+static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,
+ struct device_node *node) {

Signed-off-by: Kedareswara rao Appana <[email protected]>
---
Changes for v7:
--> New patch.

drivers/dma/xilinx/xilinx_dma.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index eaa93fe..b09a8ef 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -2484,7 +2484,8 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
* Return: 0 always.
*/
static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,
- struct device_node *node) {
+ struct device_node *node)
+{
int ret, i, nr_channels = 1;

ret = of_property_read_u32(node, "dma-channels", &nr_channels);
--
2.7.4

Subject: [PATCH v7 2/6] dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in vdma

VDMA engine default frame buffer configuration is cirular mode.
in this mode dmaengine continuously circles through h/w configured fstore
frame buffers.

When vdma h/w is configured for more than one frame.
for example h/w is configured for n number of frames, user
submits less than n number of frames and triggered the dmaengine
using issue_pending API.

since the h/w (or) driver default configuraiton is circular mode
h/w tries to write/read from an invalid frame buffer resulting
errors from the vdma dmaengine.

This patch fixes this issue by enabling the park mode as
default mode configuration for frame buffers in s/w,
so that driver can handle all cases for "k" frames where n%k==0
(n is a multiple of k) by simply replicating the frame pointers.

Signed-off-by: Kedareswara rao Appana <[email protected]>
---
Changes for v7:
---> Used park mode as default configuration as suggested
by Mike Looijmans.
---> Updated commit message as suggested by Vinod(No need to
start each line with Title cases).
Changes for v6:
---> Added Rob Acked-by
---> Updated commit message as suggested by Vinod.
Changes for v5:
---> Updated xlnx,fstore-config property to xlnx,fstore-enable
and updated description as suggested by Rob.
Changes for v4:
---> Add Check for framestore configuration on Transmit case as well
as suggested by Jose Abreu.
---> Modified the dev_dbg checks to dev_warn checks as suggested
by Jose Abreu.
Changes for v3:
---> Added Checks for frame store configuration. If frame store
Configuration is not present at the h/w level and user
Submits less frames added debug prints in the driver as relevant.
Changes for v2:
---> Fixed race conditions in the driver as suggested by Jose Abreu
---> Fixed unnecessray if else checks in the vdma_start_transfer
as suggested by Laurent Pinchart.

drivers/dma/xilinx/xilinx_dma.c | 41 +++++++++++++++++++----------------------
1 file changed, 19 insertions(+), 22 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index c246563..9063ca0 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -99,7 +99,9 @@
#define XILINX_DMA_REG_FRMPTR_STS 0x0024
#define XILINX_DMA_REG_PARK_PTR 0x0028
#define XILINX_DMA_PARK_PTR_WR_REF_SHIFT 8
+#define XILINX_DMA_PARK_PTR_WR_REF_MASK GENMASK(12, 8)
#define XILINX_DMA_PARK_PTR_RD_REF_SHIFT 0
+#define XILINX_DMA_PARK_PTR_RD_REF_MASK GENMASK(4, 0)
#define XILINX_DMA_REG_VDMA_VERSION 0x002c

/* Register Direct Mode Registers */
@@ -998,7 +1000,7 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
{
struct xilinx_vdma_config *config = &chan->config;
struct xilinx_dma_tx_descriptor *desc, *tail_desc;
- u32 reg;
+ u32 reg, j;
struct xilinx_vdma_tx_segment *tail_segment;

/* This function was invoked with lock held */
@@ -1035,10 +1037,6 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
else
reg &= ~XILINX_DMA_DMACR_FRAMECNT_EN;

- /* Configure channel to allow number frame buffers */
- dma_ctrl_write(chan, XILINX_DMA_REG_FRMSTORE,
- chan->desc_pendingcount);
-
/*
* With SG, start with circular mode, so that BDs can be fetched.
* In direct register mode, if not parking, enable circular mode
@@ -1051,17 +1049,16 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)

dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);

- if (config->park && (config->park_frm >= 0) &&
- (config->park_frm < chan->num_frms)) {
- if (chan->direction == DMA_MEM_TO_DEV)
- dma_write(chan, XILINX_DMA_REG_PARK_PTR,
- config->park_frm <<
- XILINX_DMA_PARK_PTR_RD_REF_SHIFT);
- else
- dma_write(chan, XILINX_DMA_REG_PARK_PTR,
- config->park_frm <<
- XILINX_DMA_PARK_PTR_WR_REF_SHIFT);
+ j = chan->desc_submitcount;
+ reg = dma_read(chan, XILINX_DMA_REG_PARK_PTR);
+ if (chan->direction == DMA_MEM_TO_DEV) {
+ reg &= ~XILINX_DMA_PARK_PTR_RD_REF_MASK;
+ reg |= j << XILINX_DMA_PARK_PTR_RD_REF_SHIFT;
+ } else {
+ reg &= ~XILINX_DMA_PARK_PTR_WR_REF_MASK;
+ reg |= j << XILINX_DMA_PARK_PTR_WR_REF_SHIFT;
}
+ dma_write(chan, XILINX_DMA_REG_PARK_PTR, reg);

/* Start the hardware */
xilinx_dma_start(chan);
@@ -1073,6 +1070,8 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
if (chan->has_sg) {
dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
tail_segment->phys);
+ list_splice_tail_init(&chan->pending_list, &chan->active_list);
+ chan->desc_pendingcount = 0;
} else {
struct xilinx_vdma_tx_segment *segment, *last = NULL;
int i = 0;
@@ -1102,18 +1101,13 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
vdma_desc_write(chan, XILINX_DMA_REG_FRMDLY_STRIDE,
last->hw.stride);
vdma_desc_write(chan, XILINX_DMA_REG_VSIZE, last->hw.vsize);
- }

- if (!chan->has_sg) {
- list_del(&desc->node);
- list_add_tail(&desc->node, &chan->active_list);
chan->desc_submitcount++;
chan->desc_pendingcount--;
+ list_del(&desc->node);
+ list_add_tail(&desc->node, &chan->active_list);
if (chan->desc_submitcount == chan->num_frms)
chan->desc_submitcount = 0;
- } else {
- list_splice_tail_init(&chan->pending_list, &chan->active_list);
- chan->desc_pendingcount = 0;
}

chan->idle = false;
@@ -1364,6 +1358,7 @@ static int xilinx_dma_reset(struct xilinx_dma_chan *chan)

chan->err = false;
chan->idle = true;
+ chan->desc_submitcount = 0;

return err;
}
@@ -2363,6 +2358,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
chan->ctrl_offset = XILINX_DMA_MM2S_CTRL_OFFSET;
if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
chan->desc_offset = XILINX_VDMA_MM2S_DESC_OFFSET;
+ chan->config.park = 1;

if (xdev->flush_on_fsync == XILINX_DMA_FLUSH_BOTH ||
xdev->flush_on_fsync == XILINX_DMA_FLUSH_MM2S)
@@ -2379,6 +2375,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
chan->ctrl_offset = XILINX_DMA_S2MM_CTRL_OFFSET;
if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
chan->desc_offset = XILINX_VDMA_S2MM_DESC_OFFSET;
+ chan->config.park = 1;

if (xdev->flush_on_fsync == XILINX_DMA_FLUSH_BOTH ||
xdev->flush_on_fsync == XILINX_DMA_FLUSH_S2MM)
--
2.7.4

2017-12-18 04:13:23

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH v7 1/6] dmaengine: xilinx_dma: Check for channel idle state before submitting dma descriptor

On Thu, Dec 07, 2017 at 10:51:02AM +0530, Kedareswara rao Appana wrote:

> @@ -2029,6 +2006,7 @@ static int xilinx_dma_terminate_all(struct dma_chan *dchan)
>
> /* Remove and free all of the descriptors in the lists */
> xilinx_dma_free_descriptors(chan);
> + chan->idle = true;
>
> if (chan->cyclic) {
> reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
> @@ -2344,6 +2322,12 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
> chan->has_sg = xdev->has_sg;
> chan->desc_pendingcount = 0x0;
> chan->ext_addr = xdev->ext_addr;
> + /* This variable enusres that descripotrs are not
^^^^^^^^^^

typo

--
~Vinod

2017-12-18 05:15:43

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH v7 0/6] dmaengine: xilinx_dma: Bug fixes

On Thu, Dec 07, 2017 at 10:51:01AM +0530, Kedareswara rao Appana wrote:
> This patch series fixes below bugs in DMA and VDMA IP's
> ---> Added channel idle checks in the driver before submitting the buffer descriptor to h/w.
> ---> Fixes bug in Multi frame sotres handling in VDMA
> ---> Fixes issues w.r.to multi frame descriptors submit with AXI DMA S2MM(recv) Side.
> ---> Fixed kernel doc warnings in the driver.
> ---> Fixed checkpatch errors in the driver.

Applied after applying this to fix typo. You seriously need a decent spell
checker in your editor

- /* This variable enusres that descripotrs are not
- * Submited when dma engine is in progress. This variable is
- * Added to avoid pollling for a bit in the status register to
+ /* This variable ensures that descriptors are not
+ * Submitted when dma engine is in progress. This variable is
+ * Added to avoid polling for a bit in the status register to

--
~Vinod

Subject: RE: [PATCH v7 0/6] dmaengine: xilinx_dma: Bug fixes

Hi Vinod,

>
>On Thu, Dec 07, 2017 at 10:51:01AM +0530, Kedareswara rao Appana wrote:
>> This patch series fixes below bugs in DMA and VDMA IP's
>> ---> Added channel idle checks in the driver before submitting the buffer
>descriptor to h/w.
>> ---> Fixes bug in Multi frame sotres handling in VDMA Fixes issues
>> ---> w.r.to multi frame descriptors submit with AXI DMA S2MM(recv) Side.
>> ---> Fixed kernel doc warnings in the driver.
>> ---> Fixed checkpatch errors in the driver.
>
>Applied after applying this to fix typo. You seriously need a decent spell checker in
>your editor

Thanks Vinod
Sorry for the noise around spell checks.
Will take care of it next time onwards thanks for pointing it out.

Regards,
Kedar.

>
>- /* This variable enusres that descripotrs are not
>- * Submited when dma engine is in progress. This variable is
>- * Added to avoid pollling for a bit in the status register to
>+ /* This variable ensures that descriptors are not
>+ * Submitted when dma engine is in progress. This variable is
>+ * Added to avoid polling for a bit in the status register to
>
>--
>~Vinod
>--
>To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body
>of a message to [email protected] More majordomo info at
>http://vger.kernel.org/majordomo-info.html

Subject: RE: [PATCH v7 1/6] dmaengine: xilinx_dma: Check for channel idle state before submitting dma descriptor

Hi,

Thanks for the review...

<Snip>
>
>On Thu, Dec 07, 2017 at 10:51:02AM +0530, Kedareswara rao Appana wrote:
>
>> @@ -2029,6 +2006,7 @@ static int xilinx_dma_terminate_all(struct
>> dma_chan *dchan)
>>
>> /* Remove and free all of the descriptors in the lists */
>> xilinx_dma_free_descriptors(chan);
>> + chan->idle = true;
>>
>> if (chan->cyclic) {
>> reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR); @@ -
>2344,6
>> +2322,12 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device
>*xdev,
>> chan->has_sg = xdev->has_sg;
>> chan->desc_pendingcount = 0x0;
>> chan->ext_addr = xdev->ext_addr;
>> + /* This variable enusres that descripotrs are not
> ^^^^^^^^^^
>
>typo

Since this patch got applied
Will take care of this next time on wards...
Thanks for the review...

Regards,
Kedar.

>
>--
>~Vinod