diff mbox series

[net-next,v5,07/10] dmaengine: xilinx_dma: Program interrupt delay timeout

Message ID 1691387509-2113129-8-git-send-email-radhey.shyam.pandey@amd.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series net: axienet: Introduce dmaengine | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 9 this patch: 9
netdev/cc_maintainers warning 1 maintainers not CCed: swati.agarwal@xilinx.com
netdev/build_clang success Errors and warnings before: 9 this patch: 9
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 9 this patch: 9
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 58 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Radhey Shyam Pandey Aug. 7, 2023, 5:51 a.m. UTC
Program IRQDelay for AXI DMA. The interrupt timeout mechanism causes
the DMA engine to generate an interrupt after the delay time period
has expired. It enables dmaengine to respond in real-time even though
interrupt coalescing is configured. It also remove the placeholder
for delay interrupt and merge it with frame completion interrupt.
Since by default interrupt delay timeout is disabled this feature
addition has no functional impact on VDMA, MCDMA and CDMA IP's.

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
---
Changes for v5:
- New patch in this series. Just a note that dmaengine series
  was earlier sent as separate series[1] and now it's merged
  with axiethernet series[2].
  [1]: https://lore.kernel.org/all/20221124102745.2620370-1-sarath.babu.naidu.gaddam@amd.com
  [2]: https://lore.kernel.org/all/20230630053844.1366171-1-sarath.babu.naidu.gaddam@amd.com
- Modified commit description to add "MCDMA" along with VDMA and CDMA
  IP.
- Switch to amd.com email address.
---
 drivers/dma/xilinx/xilinx_dma.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 6c1c63a38f70..e9f70cad4934 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -173,8 +173,10 @@ 
 #define XILINX_DMA_MAX_TRANS_LEN_MAX	23
 #define XILINX_DMA_V2_MAX_TRANS_LEN_MAX	26
 #define XILINX_DMA_CR_COALESCE_MAX	GENMASK(23, 16)
+#define XILINX_DMA_CR_DELAY_MAX		GENMASK(31, 24)
 #define XILINX_DMA_CR_CYCLIC_BD_EN_MASK	BIT(4)
 #define XILINX_DMA_CR_COALESCE_SHIFT	16
+#define XILINX_DMA_CR_DELAY_SHIFT	24
 #define XILINX_DMA_BD_SOP		BIT(27)
 #define XILINX_DMA_BD_EOP		BIT(26)
 #define XILINX_DMA_BD_COMP_MASK		BIT(31)
@@ -411,6 +413,7 @@  struct xilinx_dma_tx_descriptor {
  * @stop_transfer: Differentiate b/w DMA IP's quiesce
  * @tdest: TDEST value for mcdma
  * @has_vflip: S2MM vertical flip
+ * @irq_delay: Interrupt delay timeout
  */
 struct xilinx_dma_chan {
 	struct xilinx_dma_device *xdev;
@@ -449,6 +452,7 @@  struct xilinx_dma_chan {
 	int (*stop_transfer)(struct xilinx_dma_chan *chan);
 	u16 tdest;
 	bool has_vflip;
+	u8 irq_delay;
 };
 
 /**
@@ -1561,6 +1565,9 @@  static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
 	if (chan->has_sg)
 		xilinx_write(chan, XILINX_DMA_REG_CURDESC,
 			     head_desc->async_tx.phys);
+	reg  &= ~XILINX_DMA_CR_DELAY_MAX;
+	reg  |= chan->irq_delay << XILINX_DMA_CR_DELAY_SHIFT;
+	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
 
 	xilinx_dma_start(chan);
 
@@ -1898,15 +1905,8 @@  static irqreturn_t xilinx_dma_irq_handler(int irq, void *data)
 		}
 	}
 
-	if (status & XILINX_DMA_DMASR_DLY_CNT_IRQ) {
-		/*
-		 * Device takes too long to do the transfer when user requires
-		 * responsiveness.
-		 */
-		dev_dbg(chan->dev, "Inter-packet latency too long\n");
-	}
-
-	if (status & XILINX_DMA_DMASR_FRM_CNT_IRQ) {
+	if (status & (XILINX_DMA_DMASR_FRM_CNT_IRQ |
+		      XILINX_DMA_DMASR_DLY_CNT_IRQ)) {
 		spin_lock(&chan->lock);
 		xilinx_dma_complete_descriptor(chan);
 		chan->idle = true;
@@ -2833,6 +2833,8 @@  static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
 	/* Retrieve the channel properties from the device tree */
 	has_dre = of_property_read_bool(node, "xlnx,include-dre");
 
+	of_property_read_u8(node, "xlnx,irq-delay", &chan->irq_delay);
+
 	chan->genlock = of_property_read_bool(node, "xlnx,genlock-mode");
 
 	err = of_property_read_u32(node, "xlnx,datawidth", &value);