This allows custom setup of IRQ coalescing for platforms using legacy
platform_device. The irq timeout and count parameters can be used for
tuning cpu load vs. latency.
I have maintained the 0x00000400 bit in TX_CHNL_CTRL. It is specified as
unused in the documentation I have available. It does not make any
difference in the hardware I have available, so it is left in to not risk
breaking other platforms where it might be used.
Signed-off-by: Esben Haabendal <es...@geanix.com>
---
drivers/net/ethernet/xilinx/ll_temac.h | 4 +++
drivers/net/ethernet/xilinx/ll_temac_main.c | 40 +++++++++++++++++++--------
include/linux/platform_data/xilinx-ll-temac.h | 5 ++++
3 files changed, 37 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/xilinx/ll_temac.h
b/drivers/net/ethernet/xilinx/ll_temac.h
index 990f9ed..1aeda08 100644
--- a/drivers/net/ethernet/xilinx/ll_temac.h
+++ b/drivers/net/ethernet/xilinx/ll_temac.h
@@ -375,6 +375,10 @@ struct temac_local {
int tx_bd_next;
int tx_bd_tail;
int rx_bd_ci;
+
+ /* DMA channel control setup */
+ u32 tx_chnl_ctrl;
+ u32 rx_chnl_ctrl;
};
/* Wrappers for temac_ior()/temac_iow() function pointers above */
diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c
b/drivers/net/ethernet/xilinx/ll_temac_main.c
index 5e7b8f0..5833f02 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -306,18 +306,15 @@ static int temac_dma_bd_init(struct net_device *ndev)
lp->rx_bd_v[i].app0 = cpu_to_be32(STS_CTRL_APP0_IRQONEND);
}
- lp->dma_out(lp, TX_CHNL_CTRL, 0x10220400 |
- CHNL_CTRL_IRQ_EN |
- CHNL_CTRL_IRQ_DLY_EN |
- CHNL_CTRL_IRQ_COAL_EN);
- /* 0x10220483 */
- /* 0x00100483 */
- lp->dma_out(lp, RX_CHNL_CTRL, 0xff070000 |
- CHNL_CTRL_IRQ_EN |
- CHNL_CTRL_IRQ_DLY_EN |
- CHNL_CTRL_IRQ_COAL_EN |
- CHNL_CTRL_IRQ_IOE);
- /* 0xff010283 */
+ /* Configure DMA channel (irq setup) */
+ lp->dma_out(lp, TX_CHNL_CTRL, lp->tx_chnl_ctrl |
+ 0x00000400 | // Use 1 Bit Wide Counters. Currently Not Used!
+ CHNL_CTRL_IRQ_EN | CHNL_CTRL_IRQ_ERR_EN |
+ CHNL_CTRL_IRQ_DLY_EN | CHNL_CTRL_IRQ_COAL_EN);
+ lp->dma_out(lp, RX_CHNL_CTRL, lp->rx_chnl_ctrl |
+ CHNL_CTRL_IRQ_IOE |
+ CHNL_CTRL_IRQ_EN | CHNL_CTRL_IRQ_ERR_EN |
+ CHNL_CTRL_IRQ_DLY_EN | CHNL_CTRL_IRQ_COAL_EN);
lp->dma_out(lp, RX_CURDESC_PTR, lp->rx_bd_p);
lp->dma_out(lp, RX_TAILDESC_PTR,
@@ -1187,6 +1184,13 @@ static int temac_probe(struct platform_device *pdev)
lp->rx_irq = irq_of_parse_and_map(dma_np, 0);
lp->tx_irq = irq_of_parse_and_map(dma_np, 1);
+ /* Use defaults for IRQ delay/coalescing setup. These
+ * are configuration values, so does not belong in
+ * device-tree.
+ */
+ lp->tx_chnl_ctrl = 0x10220000;
+ lp->rx_chnl_ctrl = 0xff070000;
+
/* Finished with the DMA node; drop the reference */
of_node_put(dma_np);
} else if (pdata) {
@@ -1210,6 +1214,18 @@ static int temac_probe(struct platform_device *pdev)
/* Get DMA RX and TX interrupts */
lp->rx_irq = platform_get_irq(pdev, 0);
lp->tx_irq = platform_get_irq(pdev, 1);
+
+ /* IRQ delay/coalescing setup */
+ if (pdata->tx_irq_timeout || pdata->tx_irq_count)
+ lp->tx_chnl_ctrl = (pdata->tx_irq_timeout << 24) |
+ (pdata->tx_irq_count << 16);
+ else
+ lp->tx_chnl_ctrl = 0x10220000;
+ if (pdata->rx_irq_timeout || pdata->rx_irq_count)
+ lp->rx_chnl_ctrl = (pdata->rx_irq_timeout << 24) |
+ (pdata->rx_irq_count << 16);
+ else
+ lp->rx_chnl_ctrl = 0xff070000;
}
/* Error handle returned DMA RX and TX interrupts */
diff --git a/include/linux/platform_data/xilinx-ll-temac.h
b/include/linux/platform_data/xilinx-ll-temac.h
index b0b8238..368530f 100644
--- a/include/linux/platform_data/xilinx-ll-temac.h
+++ b/include/linux/platform_data/xilinx-ll-temac.h
@@ -22,6 +22,11 @@ struct ll_temac_platform_data {
* they share the same DCR bus bridge.
*/
struct mutex *indirect_mutex;
+ /* DMA channel control setup */
+ u8 tx_irq_timeout; /* TX Interrupt Delay Time-out */
+ u8 tx_irq_count; /* TX Interrupt Coalescing Threshold Count */
+ u8 rx_irq_timeout; /* RX Interrupt Delay Time-out */
+ u8 rx_irq_count; /* RX Interrupt Coalescing Threshold Count */
};
#endif /* __LINUX_XILINX_LL_TEMAC_H */
--
2.4.11
