diff mbox

[patch-net-next,v2,3/3] net: ethernet: cpsw: don't requests IRQs we don't use

Message ID 1421254729-10602-3-git-send-email-balbi@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Felipe Balbi Jan. 14, 2015, 4:58 p.m. UTC
CPSW never uses RX_THRESHOLD or MISC interrupts. In
fact, they are always kept masked in their appropriate
IRQ Enable register.

Instead of allocating an IRQ that never fires, it's best
to remove that code altogether and let future patches
implement it if anybody needs those.

Signed-off-by: Felipe Balbi <balbi@ti.com>
---
 drivers/net/ethernet/ti/cpsw.c | 55 ++++++++++++------------------------------
 1 file changed, 15 insertions(+), 40 deletions(-)

Comments

Mugunthan V N Jan. 15, 2015, 7:49 a.m. UTC | #1
On Wednesday 14 January 2015 10:28 PM, Felipe Balbi wrote:
> CPSW never uses RX_THRESHOLD or MISC interrupts. In
> fact, they are always kept masked in their appropriate
> IRQ Enable register.
> 
> Instead of allocating an IRQ that never fires, it's best
> to remove that code altogether and let future patches
> implement it if anybody needs those.
> 
> Signed-off-by: Felipe Balbi <balbi@ti.com>

Instead of introducing dummy ISR in previous patch and then removing in
this patch, both can be squashed into a single patch.

Regards
Mugunthan V N
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Felipe Balbi Jan. 15, 2015, 3:20 p.m. UTC | #2
On Thu, Jan 15, 2015 at 01:19:16PM +0530, Mugunthan V N wrote:
> On Wednesday 14 January 2015 10:28 PM, Felipe Balbi wrote:
> > CPSW never uses RX_THRESHOLD or MISC interrupts. In
> > fact, they are always kept masked in their appropriate
> > IRQ Enable register.
> > 
> > Instead of allocating an IRQ that never fires, it's best
> > to remove that code altogether and let future patches
> > implement it if anybody needs those.
> > 
> > Signed-off-by: Felipe Balbi <balbi@ti.com>
> 
> Instead of introducing dummy ISR in previous patch and then removing in
> this patch, both can be squashed into a single patch.

sure they can. I decided to split to ease review and to make sure only
one thing happens in a single patch.
David Miller Jan. 15, 2015, 11:16 p.m. UTC | #3
From: Felipe Balbi <balbi@ti.com>
Date: Thu, 15 Jan 2015 09:20:53 -0600

> On Thu, Jan 15, 2015 at 01:19:16PM +0530, Mugunthan V N wrote:
>> On Wednesday 14 January 2015 10:28 PM, Felipe Balbi wrote:
>> > CPSW never uses RX_THRESHOLD or MISC interrupts. In
>> > fact, they are always kept masked in their appropriate
>> > IRQ Enable register.
>> > 
>> > Instead of allocating an IRQ that never fires, it's best
>> > to remove that code altogether and let future patches
>> > implement it if anybody needs those.
>> > 
>> > Signed-off-by: Felipe Balbi <balbi@ti.com>
>> 
>> Instead of introducing dummy ISR in previous patch and then removing in
>> this patch, both can be squashed into a single patch.
> 
> sure they can. I decided to split to ease review and to make sure only
> one thing happens in a single patch.

Indeed, I agree that adding something as a placeholder that just gets
immediately removed should be avoided unless it is extremely difficult
to do so.
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Felipe Balbi Jan. 16, 2015, 1:28 a.m. UTC | #4
On Thu, Jan 15, 2015 at 06:16:15PM -0500, David Miller wrote:
> From: Felipe Balbi <balbi@ti.com>
> Date: Thu, 15 Jan 2015 09:20:53 -0600
> 
> > On Thu, Jan 15, 2015 at 01:19:16PM +0530, Mugunthan V N wrote:
> >> On Wednesday 14 January 2015 10:28 PM, Felipe Balbi wrote:
> >> > CPSW never uses RX_THRESHOLD or MISC interrupts. In
> >> > fact, they are always kept masked in their appropriate
> >> > IRQ Enable register.
> >> > 
> >> > Instead of allocating an IRQ that never fires, it's best
> >> > to remove that code altogether and let future patches
> >> > implement it if anybody needs those.
> >> > 
> >> > Signed-off-by: Felipe Balbi <balbi@ti.com>
> >> 
> >> Instead of introducing dummy ISR in previous patch and then removing in
> >> this patch, both can be squashed into a single patch.
> > 
> > sure they can. I decided to split to ease review and to make sure only
> > one thing happens in a single patch.
> 
> Indeed, I agree that adding something as a placeholder that just gets
> immediately removed should be avoided unless it is extremely difficult
> to do so.

what does this mean ? you prefer both patches to be combined ?
David Miller Jan. 16, 2015, 4:36 a.m. UTC | #5
From: Felipe Balbi <balbi@ti.com>
Date: Thu, 15 Jan 2015 19:28:52 -0600

> On Thu, Jan 15, 2015 at 06:16:15PM -0500, David Miller wrote:
>> Indeed, I agree that adding something as a placeholder that just gets
>> immediately removed should be avoided unless it is extremely difficult
>> to do so.
> 
> what does this mean ? you prefer both patches to be combined ?

Yes, something like that.
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diff mbox

Patch

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index c6c483f3e49f..ba09ff3c1695 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -754,16 +754,6 @@  requeue:
 		dev_kfree_skb_any(new_skb);
 }
 
-static irqreturn_t cpsw_dummy_interrupt(int irq, void *dev_id)
-{
-	struct cpsw_priv *priv = dev_id;
-	int value = irq - priv->irqs_table[0];
-
-	cpdma_ctlr_eoi(priv->dma, value);
-
-	return IRQ_HANDLED;
-}
-
 static irqreturn_t cpsw_tx_interrupt(int irq, void *dev_id)
 {
 	struct cpsw_priv *priv = dev_id;
@@ -1635,8 +1625,8 @@  static void cpsw_ndo_poll_controller(struct net_device *ndev)
 
 	cpsw_intr_disable(priv);
 	cpdma_ctlr_int_ctrl(priv->dma, false);
-	cpsw_rx_interrupt(priv->irq[1], priv);
-	cpsw_tx_interrupt(priv->irq[2], priv);
+	cpsw_rx_interrupt(priv->irq[0], priv);
+	cpsw_tx_interrupt(priv->irq[1], priv);
 	cpdma_ctlr_int_ctrl(priv->dma, true);
 	cpsw_intr_enable(priv);
 }
@@ -2358,30 +2348,27 @@  static int cpsw_probe(struct platform_device *pdev)
 		goto clean_dma_ret;
 	}
 
-	ndev->irq = platform_get_irq(pdev, 0);
+	ndev->irq = platform_get_irq(pdev, 1);
 	if (ndev->irq < 0) {
 		dev_err(priv->dev, "error getting irq resource\n");
 		ret = -ENOENT;
 		goto clean_ale_ret;
 	}
 
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0)
-		goto clean_ale_ret;
-
-	priv->irqs_table[0] = irq;
-	ret = devm_request_irq(&pdev->dev, irq, cpsw_dummy_interrupt,
-			       0, dev_name(&pdev->dev), priv);
-	if (ret < 0) {
-		dev_err(priv->dev, "error attaching irq (%d)\n", ret);
-		goto clean_ale_ret;
-	}
+	/* Grab RX and TX IRQs. Note that we also have RX_THRESHOLD and
+	 * MISC IRQs which are always kept disabled with this driver so
+	 * we will not request them.
+	 *
+	 * If anyone wants to implement support for those, make sure to
+	 * first request and append them to irqs_table array.
+	 */
 
+	/* RX IRQ */
 	irq = platform_get_irq(pdev, 1);
 	if (irq < 0)
 		goto clean_ale_ret;
 
-	priv->irqs_table[1] = irq;
+	priv->irqs_table[0] = irq;
 	ret = devm_request_irq(&pdev->dev, irq, cpsw_rx_interrupt,
 			       0, dev_name(&pdev->dev), priv);
 	if (ret < 0) {
@@ -2389,31 +2376,19 @@  static int cpsw_probe(struct platform_device *pdev)
 		goto clean_ale_ret;
 	}
 
+	/* TX IRQ */
 	irq = platform_get_irq(pdev, 2);
 	if (irq < 0)
 		goto clean_ale_ret;
 
-	priv->irqs_table[2] = irq;
+	priv->irqs_table[1] = irq;
 	ret = devm_request_irq(&pdev->dev, irq, cpsw_tx_interrupt,
 			       0, dev_name(&pdev->dev), priv);
 	if (ret < 0) {
 		dev_err(priv->dev, "error attaching irq (%d)\n", ret);
 		goto clean_ale_ret;
 	}
-
-	irq = platform_get_irq(pdev, 3);
-	if (irq < 0)
-		goto clean_ale_ret;
-
-	priv->irqs_table[3] = irq;
-	ret = devm_request_irq(&pdev->dev, irq, cpsw_dummy_interrupt,
-			       0, dev_name(&pdev->dev), priv);
-	if (ret < 0) {
-		dev_err(priv->dev, "error attaching irq (%d)\n", ret);
-		goto clean_ale_ret;
-	}
-
-	priv->num_irqs = 4;
+	priv->num_irqs = 2;
 
 	ndev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;