[PATCH] net: ks8851: convert to threaded IRQ

[PATCH] net: ks8851: convert to threaded IRQ

[Felipe Balbi]

just as it should have been. It also helps
removing the, now unnecessary, workqueue.

Signed-off-by: Felipe Balbi <balbi@ti.com>
---
 drivers/net/ethernet/micrel/ks8851.c | 41 ++++++++++--------------------------
 1 file changed, 11 insertions(+), 30 deletions(-)

diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c
index 286816a..48ecb36 100644
--- a/drivers/net/ethernet/micrel/ks8851.c
+++ b/drivers/net/ethernet/micrel/ks8851.c
@@ -69,7 +69,6 @@ union ks8851_tx_hdr {
  * @mii: The MII state information for the mii calls.
  * @rxctrl: RX settings for @rxctrl_work.
  * @tx_work: Work queue for tx packets
- * @irq_work: Work queue for servicing interrupts
  * @rxctrl_work: Work queue for updating RX mode and multicast lists
  * @txq: Queue of packets for transmission.
  * @spi_msg1: pre-setup SPI transfer with one message, @spi_xfer1.
@@ -121,7 +120,6 @@ struct ks8851_net {
 	struct ks8851_rxctrl	rxctrl;
 
 	struct work_struct	tx_work;
-	struct work_struct	irq_work;
 	struct work_struct	rxctrl_work;
 
 	struct sk_buff_head	txq;
@@ -444,23 +442,6 @@ static void ks8851_init_mac(struct ks8851_net *ks)
 }
 
 /**
- * ks8851_irq - device interrupt handler
- * @irq: Interrupt number passed from the IRQ handler.
- * @pw: The private word passed to register_irq(), our struct ks8851_net.
- *
- * Disable the interrupt from happening again until we've processed the
- * current status by scheduling ks8851_irq_work().
- */
-static irqreturn_t ks8851_irq(int irq, void *pw)
-{
-	struct ks8851_net *ks = pw;
-
-	disable_irq_nosync(irq);
-	schedule_work(&ks->irq_work);
-	return IRQ_HANDLED;
-}
-
-/**
  * ks8851_rdfifo - read data from the receive fifo
  * @ks: The device state.
  * @buff: The buffer address
@@ -595,19 +576,20 @@ static void ks8851_rx_pkts(struct ks8851_net *ks)
 }
 
 /**
- * ks8851_irq_work - work queue handler for dealing with interrupt requests
- * @work: The work structure that was scheduled by schedule_work()
+ * ks8851_irq - IRQ handler for dealing with interrupt requests
+ * @irq: IRQ number
+ * @_ks: cookie
  *
- * This is the handler invoked when the ks8851_irq() is called to find out
- * what happened, as we cannot allow ourselves to sleep whilst waiting for
- * anything other process has the chip's lock.
+ * This handler is invoked when the IRQ line asserts to find out what happened.
+ * As we cannot allow ourselves to sleep in HARDIRQ context, this handler runs
+ * in thread context.
  *
  * Read the interrupt status, work out what needs to be done and then clear
  * any of the interrupts that are not needed.
  */
-static void ks8851_irq_work(struct work_struct *work)
+static irqreturn_t ks8851_irq(int irq, void *_ks)
 {
-	struct ks8851_net *ks = container_of(work, struct ks8851_net, irq_work);
+	struct ks8851_net *ks = _ks;
 	unsigned status;
 	unsigned handled = 0;
 
@@ -688,7 +670,7 @@ static void ks8851_irq_work(struct work_struct *work)
 	if (status & IRQ_TXI)
 		netif_wake_queue(ks->netdev);
 
-	enable_irq(ks->netdev->irq);
+	return IRQ_HANDLED;
 }
 
 /**
@@ -896,7 +878,6 @@ static int ks8851_net_stop(struct net_device *dev)
 	mutex_unlock(&ks->lock);
 
 	/* stop any outstanding work */
-	flush_work(&ks->irq_work);
 	flush_work(&ks->tx_work);
 	flush_work(&ks->rxctrl_work);
 
@@ -1438,7 +1419,6 @@ static int ks8851_probe(struct spi_device *spi)
 	spin_lock_init(&ks->statelock);
 
 	INIT_WORK(&ks->tx_work, ks8851_tx_work);
-	INIT_WORK(&ks->irq_work, ks8851_irq_work);
 	INIT_WORK(&ks->rxctrl_work, ks8851_rxctrl_work);
 
 	/* initialise pre-made spi transfer messages */
@@ -1505,7 +1485,8 @@ static int ks8851_probe(struct spi_device *spi)
 	ks8851_read_selftest(ks);
 	ks8851_init_mac(ks);
 
-	ret = request_irq(spi->irq, ks8851_irq, IRQF_TRIGGER_LOW,
+	ret = request_threaded_irq(spi->irq, NULL, ks8851_irq,
+			IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 			  ndev->name, ks);
 	if (ret < 0) {
 		dev_err(&spi->dev, "failed to get irq\n");
-- 
1.8.1.rc1.5.g7e0651a

Re: [PATCH] net: ks8851: convert to threaded IRQ

[David Miller]

From: Felipe Balbi <balbi@ti.com>
Date: Wed, 23 Jan 2013 15:51:38 +0200

> @@ -1505,7 +1485,8 @@ static int ks8851_probe(struct spi_device *spi)
>  	ks8851_read_selftest(ks);
>  	ks8851_init_mac(ks);
>  
> -	ret = request_irq(spi->irq, ks8851_irq, IRQF_TRIGGER_LOW,
> +	ret = request_threaded_irq(spi->irq, NULL, ks8851_irq,
> +			IRQF_TRIGGER_LOW | IRQF_ONESHOT,
>  			  ndev->name, ks);

You need to indent the second and third line of this function call
properly.  It should be:

	ret = function_call(arg1, arg2,
			    arg3, arg4,
			    arg5, arg6, etc.);

not what you have there now which has every line indented differently.

Re: [PATCH] net: ks8851: convert to threaded IRQ

[Joe Perches]

On Mon, 2013-01-28 at 22:31 -0500, David Miller wrote:
> From: Felipe Balbi <balbi@ti.com>
> Date: Wed, 23 Jan 2013 15:51:38 +0200
[]
> > @@ -1505,7 +1485,8 @@ static int ks8851_probe(struct spi_device *spi)
[]
> > -     ret = request_irq(spi->irq, ks8851_irq, IRQF_TRIGGER_LOW,
> > +     ret = request_threaded_irq(spi->irq, NULL, ks8851_irq,
> > +                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> >                         ndev->name, ks);
> 
> You need to indent the second and third line of this function call
> properly.  It should be:
> 
>         ret = function_call(arg1, arg2,
>                             arg3, arg4,
>                             arg5, arg6, etc.);

Instead of writing all these emails all the time,
maybe it'd be better to make the checkpatch messages
that are currently emitted only with the --strict
option (like parenthesis alignment) emitted whenever
working on files in drivers/net/ and net/.
---
 scripts/checkpatch.pl | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 9cec6dd..da1d15a 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -35,6 +35,8 @@ my $help = 0;
 my $configuration_file = ".checkpatch.conf";
 my $max_line_length = 80;
 
+my $realfile = '';
+
 sub help {
 	my ($exitcode) = @_;
 
@@ -1287,7 +1289,9 @@ sub WARN {
 	}
 }
 sub CHK {
-	if ($check && report("CHECK", $_[0], $_[1])) {
+	if ($realfile =~ m@^(drivers/net|net/)@) {
+		WARN($_[0], $_[1]);
+	} elsif ($check && report("CHECK", $_[0], $_[1])) {
 		our $clean = 0;
 		our $cnt_chk++;
 	}
@@ -1381,7 +1385,7 @@ sub process {
 	our $cnt_chk = 0;
 
 	# Trace the real file/line as we go.
-	my $realfile = '';
+	$realfile = '';
 	my $realline = 0;
 	my $realcnt = 0;
 	my $here = '';

[PATCH] net: ks8851: convert to threaded IRQ

[Felipe Balbi]

just as it should have been. It also helps
removing the, now unnecessary, workqueue.

Signed-off-by: Felipe Balbi <balbi@ti.com>
---
 drivers/net/ethernet/micrel/ks8851.c | 43 ++++++++++--------------------------
 1 file changed, 12 insertions(+), 31 deletions(-)

diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c
index 286816a..e29ad2e 100644
--- a/drivers/net/ethernet/micrel/ks8851.c
+++ b/drivers/net/ethernet/micrel/ks8851.c
@@ -69,7 +69,6 @@ union ks8851_tx_hdr {
  * @mii: The MII state information for the mii calls.
  * @rxctrl: RX settings for @rxctrl_work.
  * @tx_work: Work queue for tx packets
- * @irq_work: Work queue for servicing interrupts
  * @rxctrl_work: Work queue for updating RX mode and multicast lists
  * @txq: Queue of packets for transmission.
  * @spi_msg1: pre-setup SPI transfer with one message, @spi_xfer1.
@@ -121,7 +120,6 @@ struct ks8851_net {
 	struct ks8851_rxctrl	rxctrl;
 
 	struct work_struct	tx_work;
-	struct work_struct	irq_work;
 	struct work_struct	rxctrl_work;
 
 	struct sk_buff_head	txq;
@@ -444,23 +442,6 @@ static void ks8851_init_mac(struct ks8851_net *ks)
 }
 
 /**
- * ks8851_irq - device interrupt handler
- * @irq: Interrupt number passed from the IRQ handler.
- * @pw: The private word passed to register_irq(), our struct ks8851_net.
- *
- * Disable the interrupt from happening again until we've processed the
- * current status by scheduling ks8851_irq_work().
- */
-static irqreturn_t ks8851_irq(int irq, void *pw)
-{
-	struct ks8851_net *ks = pw;
-
-	disable_irq_nosync(irq);
-	schedule_work(&ks->irq_work);
-	return IRQ_HANDLED;
-}
-
-/**
  * ks8851_rdfifo - read data from the receive fifo
  * @ks: The device state.
  * @buff: The buffer address
@@ -595,19 +576,20 @@ static void ks8851_rx_pkts(struct ks8851_net *ks)
 }
 
 /**
- * ks8851_irq_work - work queue handler for dealing with interrupt requests
- * @work: The work structure that was scheduled by schedule_work()
+ * ks8851_irq - IRQ handler for dealing with interrupt requests
+ * @irq: IRQ number
+ * @_ks: cookie
  *
- * This is the handler invoked when the ks8851_irq() is called to find out
- * what happened, as we cannot allow ourselves to sleep whilst waiting for
- * anything other process has the chip's lock.
+ * This handler is invoked when the IRQ line asserts to find out what happened.
+ * As we cannot allow ourselves to sleep in HARDIRQ context, this handler runs
+ * in thread context.
  *
  * Read the interrupt status, work out what needs to be done and then clear
  * any of the interrupts that are not needed.
  */
-static void ks8851_irq_work(struct work_struct *work)
+static irqreturn_t ks8851_irq(int irq, void *_ks)
 {
-	struct ks8851_net *ks = container_of(work, struct ks8851_net, irq_work);
+	struct ks8851_net *ks = _ks;
 	unsigned status;
 	unsigned handled = 0;
 
@@ -688,7 +670,7 @@ static void ks8851_irq_work(struct work_struct *work)
 	if (status & IRQ_TXI)
 		netif_wake_queue(ks->netdev);
 
-	enable_irq(ks->netdev->irq);
+	return IRQ_HANDLED;
 }
 
 /**
@@ -896,7 +878,6 @@ static int ks8851_net_stop(struct net_device *dev)
 	mutex_unlock(&ks->lock);
 
 	/* stop any outstanding work */
-	flush_work(&ks->irq_work);
 	flush_work(&ks->tx_work);
 	flush_work(&ks->rxctrl_work);
 
@@ -1438,7 +1419,6 @@ static int ks8851_probe(struct spi_device *spi)
 	spin_lock_init(&ks->statelock);
 
 	INIT_WORK(&ks->tx_work, ks8851_tx_work);
-	INIT_WORK(&ks->irq_work, ks8851_irq_work);
 	INIT_WORK(&ks->rxctrl_work, ks8851_rxctrl_work);
 
 	/* initialise pre-made spi transfer messages */
@@ -1505,8 +1485,9 @@ static int ks8851_probe(struct spi_device *spi)
 	ks8851_read_selftest(ks);
 	ks8851_init_mac(ks);
 
-	ret = request_irq(spi->irq, ks8851_irq, IRQF_TRIGGER_LOW,
-			  ndev->name, ks);
+	ret = request_threaded_irq(spi->irq, NULL, ks8851_irq,
+				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+				   ndev->name, ks);
 	if (ret < 0) {
 		dev_err(&spi->dev, "failed to get irq\n");
 		goto err_irq;
-- 
1.8.1.rc1.5.g7e0651a

Re: [PATCH] net: ks8851: convert to threaded IRQ

[David Miller]

From: Felipe Balbi <balbi@ti.com>
Date: Tue, 29 Jan 2013 09:16:30 +0200

> just as it should have been. It also helps
> removing the, now unnecessary, workqueue.
> 
> Signed-off-by: Felipe Balbi <balbi@ti.com>

Applied.

Re: [PATCH] net: ks8851: convert to threaded IRQ

[Stephen Boyd]

On 01/28/13 23:16, Felipe Balbi wrote:
> just as it should have been. It also helps
> removing the, now unnecessary, workqueue.

Tested-by: Stephen Boyd <sboyd@codeaurora.org>

> Signed-off-by: Felipe Balbi <balbi@ti.com>
> ---
> @@ -1505,8 +1485,9 @@ static int ks8851_probe(struct spi_device *spi)
>  	ks8851_read_selftest(ks);
>  	ks8851_init_mac(ks);
>  
> -	ret = request_irq(spi->irq, ks8851_irq, IRQF_TRIGGER_LOW,
> -			  ndev->name, ks);
> +	ret = request_threaded_irq(spi->irq, NULL, ks8851_irq,
> +				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> +				   ndev->name, ks);

I did notice one thing here. The name of the thread is irq/378-eth%d
(where 378 is the irq number). It seems that ndev->name is not fully
formed until register_netdev() is called and so when the thread is
created, the malformed name is used for the thread name.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

Re: [PATCH] net: ks8851: convert to threaded IRQ

[Felipe Balbi]

[-- Attachment #1: Type: text/plain, Size: 1104 bytes --]

On Tue, Jan 29, 2013 at 10:53:08AM -0800, Stephen Boyd wrote:
> On 01/28/13 23:16, Felipe Balbi wrote:
> > just as it should have been. It also helps
> > removing the, now unnecessary, workqueue.
> 
> Tested-by: Stephen Boyd <sboyd@codeaurora.org>
> 
> > Signed-off-by: Felipe Balbi <balbi@ti.com>
> > ---
> > @@ -1505,8 +1485,9 @@ static int ks8851_probe(struct spi_device *spi)
> >  	ks8851_read_selftest(ks);
> >  	ks8851_init_mac(ks);
> >  
> > -	ret = request_irq(spi->irq, ks8851_irq, IRQF_TRIGGER_LOW,
> > -			  ndev->name, ks);
> > +	ret = request_threaded_irq(spi->irq, NULL, ks8851_irq,
> > +				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> > +				   ndev->name, ks);
> 
> I did notice one thing here. The name of the thread is irq/378-eth%d
> (where 378 is the irq number). It seems that ndev->name is not fully
> formed until register_netdev() is called and so when the thread is
> created, the malformed name is used for the thread name.

that would be a problem even before the conversion to threaded irq, the
only difference is that 378- would be omitted.

-- 
balbi

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]

Re: [PATCH] net: ks8851: convert to threaded IRQ

[Stephen Boyd]

On 01/29/13 11:02, Felipe Balbi wrote:
> On Tue, Jan 29, 2013 at 10:53:08AM -0800, Stephen Boyd wrote:
>> On 01/28/13 23:16, Felipe Balbi wrote:
>>> just as it should have been. It also helps
>>> removing the, now unnecessary, workqueue.
>> Tested-by: Stephen Boyd <sboyd@codeaurora.org>
>>
>>> Signed-off-by: Felipe Balbi <balbi@ti.com>
>>> ---
>>> @@ -1505,8 +1485,9 @@ static int ks8851_probe(struct spi_device *spi)
>>>  	ks8851_read_selftest(ks);
>>>  	ks8851_init_mac(ks);
>>>  
>>> -	ret = request_irq(spi->irq, ks8851_irq, IRQF_TRIGGER_LOW,
>>> -			  ndev->name, ks);
>>> +	ret = request_threaded_irq(spi->irq, NULL, ks8851_irq,
>>> +				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
>>> +				   ndev->name, ks);
>> I did notice one thing here. The name of the thread is irq/378-eth%d
>> (where 378 is the irq number). It seems that ndev->name is not fully
>> formed until register_netdev() is called and so when the thread is
>> created, the malformed name is used for the thread name.
> that would be a problem even before the conversion to threaded irq, the
> only difference is that 378- would be omitted.
>

It doesn't seem to be a problem in the non-threaded case presumably
because the name is pointed to directly, instead of being copied, for
the /proc/interrupts case. In other words, /proc/interrupts shows eth0
instead of eth%d with and without this patch applied.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation