On 14-01-17 06:35, Kedareswara rao Appana wrote:
When VDMA is configured for more than one frame in the h/w. For example h/w is configured for n number of frames, user Submits n number of frames and triggered the DMA using issue_pending API. In the current driver flow we are submitting one frame at a time, But we should submit all the n number of frames at one time As the h/w is configured for n number of frames.
The hardware can always handle a single frame submission, by using the "park" bit. This would make a good "cyclic" implementation too (using vdma as framebuffer).
It could also handle all cases for "k" frames where n%k==0 (n is a multiple of k) by simply replicating the frame pointers.
This patch fixes this issue. Acked-by: Rob Herring <robh@xxxxxxxxxx> Reviewed-by: Jose Abreu <joabreu@xxxxxxxxxxxx> Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx> --- 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. .../devicetree/bindings/dma/xilinx/xilinx_dma.txt | 2 + drivers/dma/xilinx/xilinx_dma.c | 78 +++++++++++++++------- 2 files changed, 57 insertions(+), 23 deletions(-) diff --git a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt index a2b8bfa..e951c09 100644 --- a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt +++ b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt @@ -66,6 +66,8 @@ Optional child node properties: Optional child node properties for VDMA: - xlnx,genlock-mode: Tells Genlock synchronization is enabled/disabled in hardware. +- xlnx,fstore-enable: boolean; if defined, it indicates that controller + supports frame store configuration. Optional child node properties for AXI DMA: -dma-channels: Number of dma channels in child node. diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c index 5eeea57..edb5b71 100644 --- a/drivers/dma/xilinx/xilinx_dma.c +++ b/drivers/dma/xilinx/xilinx_dma.c @@ -322,6 +322,7 @@ struct xilinx_dma_tx_descriptor { * @genlock: Support genlock mode * @err: Channel has errors * @idle: Check for channel idle + * @has_fstoreen: Check for frame store configuration * @tasklet: Cleanup work after irq * @config: Device configuration info * @flush_on_fsync: Flush on Frame sync @@ -353,6 +354,7 @@ struct xilinx_dma_chan { bool genlock; bool err; bool idle; + bool has_fstoreen; struct tasklet_struct tasklet; struct xilinx_vdma_config config; bool flush_on_fsync; @@ -990,6 +992,27 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan) if (list_empty(&chan->pending_list)) return; + /* + * Note: When VDMA is built with default h/w configuration + * User should submit frames upto H/W configured. + * If users submits less than h/w configured + * VDMA engine tries to write to a invalid location + * Results undefined behaviour/memory corruption. + * + * If user would like to submit frames less than h/w capable + * On S2MM side please enable debug info 13 at the h/w level + * On MM2S side please enable debug info 6 at the h/w level + * It will allows the frame buffers numbers to be modified at runtime. + */ + if (!chan->has_fstoreen && + chan->desc_pendingcount < chan->num_frms) { + dev_warn(chan->dev, "Frame Store Configuration is not enabled at the\n"); + dev_warn(chan->dev, "H/w level enable Debug info 13 or 6 at the h/w level\n"); + dev_warn(chan->dev, "OR Submit the frames upto h/w Capable\n\r"); + + return; + } + desc = list_first_entry(&chan->pending_list, struct xilinx_dma_tx_descriptor, node); tail_desc = list_last_entry(&chan->pending_list, @@ -1052,25 +1075,38 @@ 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; + int i = 0, j = 0; if (chan->desc_submitcount < chan->num_frms) i = chan->desc_submitcount; - list_for_each_entry(segment, &desc->segments, node) { - if (chan->ext_addr) - vdma_desc_write_64(chan, - XILINX_VDMA_REG_START_ADDRESS_64(i++), - segment->hw.buf_addr, - segment->hw.buf_addr_msb); - else - vdma_desc_write(chan, - XILINX_VDMA_REG_START_ADDRESS(i++), - segment->hw.buf_addr); - - last = segment; + for (j = 0; j < chan->num_frms; ) { + list_for_each_entry(segment, &desc->segments, node) { + if (chan->ext_addr) + vdma_desc_write_64(chan, + XILINX_VDMA_REG_START_ADDRESS_64(i++), + segment->hw.buf_addr, + segment->hw.buf_addr_msb); + else + vdma_desc_write(chan, + XILINX_VDMA_REG_START_ADDRESS(i++), + segment->hw.buf_addr); + + last = segment; + } + list_del(&desc->node); + list_add_tail(&desc->node, &chan->active_list); + j++; + if (list_empty(&chan->pending_list) || + (i == chan->num_frms)) + break; + desc = list_first_entry(&chan->pending_list, + struct xilinx_dma_tx_descriptor, + node); } if (!last) @@ -1081,20 +1117,14 @@ 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); - } - chan->idle = false; - if (!chan->has_sg) { - list_del(&desc->node); - list_add_tail(&desc->node, &chan->active_list); - chan->desc_submitcount++; - chan->desc_pendingcount--; + chan->desc_submitcount += j; + chan->desc_pendingcount -= j; 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; } /** @@ -1342,6 +1372,7 @@ static int xilinx_dma_reset(struct xilinx_dma_chan *chan) chan->err = false; chan->idle = true; + chan->desc_submitcount = 0; return err; } @@ -2320,6 +2351,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev, has_dre = of_property_read_bool(node, "xlnx,include-dre"); chan->genlock = of_property_read_bool(node, "xlnx,genlock-mode"); + chan->has_fstoreen = of_property_read_bool(node, "xlnx,fstore-enable"); err = of_property_read_u32(node, "xlnx,datawidth", &value); if (err) {
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