diff mbox series

[net-next,4/7] net: axienet: don't set IRQ timer when IRQ delay not used

Message ID 20220304224205.3198029-5-robert.hancock@calian.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series NAPI/GRO support for axienet driver | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers warning 1 maintainers not CCed: linux-arm-kernel@lists.infradead.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 28 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Robert Hancock March 4, 2022, 10:42 p.m. UTC
When the RX or TX coalesce count is set to 1, there's no point in
setting the delay timer value since an interrupt will already be raised
on every packet, and the delay interrupt just causes extra pointless
interrupts.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
---
 .../net/ethernet/xilinx/xilinx_axienet_main.c  | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index d705b62c3958..b374800279e7 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -236,14 +236,24 @@  static void axienet_dma_start(struct axienet_local *lp)
 
 	/* Start updating the Rx channel control register */
 	rx_cr = (lp->coalesce_count_rx << XAXIDMA_COALESCE_SHIFT) |
-		(XAXIDMA_DFT_RX_WAITBOUND << XAXIDMA_DELAY_SHIFT) |
-		XAXIDMA_IRQ_ALL_MASK;
+		XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_ERROR_MASK;
+	/* Only set interrupt delay timer if not generating an interrupt on
+	 * the first RX packet. Otherwise leave at 0 to disable delay interrupt.
+	 */
+	if (lp->coalesce_count_rx > 1)
+		rx_cr |= (XAXIDMA_DFT_RX_WAITBOUND << XAXIDMA_DELAY_SHIFT) |
+			 XAXIDMA_IRQ_DELAY_MASK;
 	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, rx_cr);
 
 	/* Start updating the Tx channel control register */
 	tx_cr = (lp->coalesce_count_tx << XAXIDMA_COALESCE_SHIFT) |
-		(XAXIDMA_DFT_TX_WAITBOUND << XAXIDMA_DELAY_SHIFT) |
-		XAXIDMA_IRQ_ALL_MASK;
+		XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_ERROR_MASK;
+	/* Only set interrupt delay timer if not generating an interrupt on
+	 * the first TX packet. Otherwise leave at 0 to disable delay interrupt.
+	 */
+	if (lp->coalesce_count_tx > 1)
+		tx_cr |= (XAXIDMA_DFT_TX_WAITBOUND << XAXIDMA_DELAY_SHIFT) |
+			 XAXIDMA_IRQ_DELAY_MASK;
 	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, tx_cr);
 
 	/* Populate the tail pointer and bring the Rx Axi DMA engine out of