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* [PATCH 1/1] net: can: sja1000: Validate initialization state in start method
@ 2014-08-08 12:30 Mirza Krak
  2014-08-14 10:18 ` Marc Kleine-Budde
  0 siblings, 1 reply; 4+ messages in thread
From: Mirza Krak @ 2014-08-08 12:30 UTC (permalink / raw)
  To: linux-can, mkl; +Cc: Mirza Krak

When sja1000 is not compiled as module the SJA1000 chip is only
initialized during device registration on kernel boot. Should the chip
get a hardware reset there is no way to reinitialize it without re-
booting the Linux kernel.

This patch adds a check in sja1000_start if the chip is initialized, if
not we initialize it.

Signed-off-by: Mirza Krak <mirza.krak@hostmobility.com>
---
 drivers/net/can/sja1000/sja1000.c | 62 +++++++++++++++++++++------------------
 1 file changed, 33 insertions(+), 29 deletions(-)

diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index f31499a..ba9d423 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -170,6 +170,35 @@ static void set_normal_mode(struct net_device *dev)
 	netdev_err(dev, "setting SJA1000 into normal mode failed!\n");
 }

+/*
+ * initialize SJA1000 chip:
+ *   - reset chip
+ *   - set output mode
+ *   - set baudrate
+ *   - enable interrupts
+ *   - start operating mode
+ */
+static void chipset_init(struct net_device *dev)
+{
+	struct sja1000_priv *priv = netdev_priv(dev);
+
+	/* set clock divider and output control register */
+	priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
+
+	/* set acceptance filter (accept all) */
+	priv->write_reg(priv, SJA1000_ACCC0, 0x00);
+	priv->write_reg(priv, SJA1000_ACCC1, 0x00);
+	priv->write_reg(priv, SJA1000_ACCC2, 0x00);
+	priv->write_reg(priv, SJA1000_ACCC3, 0x00);
+
+	priv->write_reg(priv, SJA1000_ACCM0, 0xFF);
+	priv->write_reg(priv, SJA1000_ACCM1, 0xFF);
+	priv->write_reg(priv, SJA1000_ACCM2, 0xFF);
+	priv->write_reg(priv, SJA1000_ACCM3, 0xFF);
+
+	priv->write_reg(priv, SJA1000_OCR, priv->ocr | OCR_MODE_NORMAL);
+}
+
 static void sja1000_start(struct net_device *dev)
 {
 	struct sja1000_priv *priv = netdev_priv(dev);
@@ -178,6 +207,10 @@ static void sja1000_start(struct net_device *dev)
 	if (priv->can.state != CAN_STATE_STOPPED)
 		set_reset_mode(dev);

+	/* Initialize chip if uninitialized at this stage */
+	if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
+		chipset_init(dev);
+
 	/* Clear error counters and error code capture */
 	priv->write_reg(priv, SJA1000_TXERR, 0x0);
 	priv->write_reg(priv, SJA1000_RXERR, 0x0);
@@ -235,35 +268,6 @@ static int sja1000_get_berr_counter(const struct net_device *dev,
 }

 /*
- * initialize SJA1000 chip:
- *   - reset chip
- *   - set output mode
- *   - set baudrate
- *   - enable interrupts
- *   - start operating mode
- */
-static void chipset_init(struct net_device *dev)
-{
-	struct sja1000_priv *priv = netdev_priv(dev);
-
-	/* set clock divider and output control register */
-	priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN);
-
-	/* set acceptance filter (accept all) */
-	priv->write_reg(priv, SJA1000_ACCC0, 0x00);
-	priv->write_reg(priv, SJA1000_ACCC1, 0x00);
-	priv->write_reg(priv, SJA1000_ACCC2, 0x00);
-	priv->write_reg(priv, SJA1000_ACCC3, 0x00);
-
-	priv->write_reg(priv, SJA1000_ACCM0, 0xFF);
-	priv->write_reg(priv, SJA1000_ACCM1, 0xFF);
-	priv->write_reg(priv, SJA1000_ACCM2, 0xFF);
-	priv->write_reg(priv, SJA1000_ACCM3, 0xFF);
-
-	priv->write_reg(priv, SJA1000_OCR, priv->ocr | OCR_MODE_NORMAL);
-}
-
-/*
  * transmit a CAN message
  * message layout in the sk_buff should be like this:
  * xx xx xx xx	 ff	 ll   00 11 22 33 44 55 66 77
--
1.9.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH 1/1] net: can: sja1000: Validate initialization state in start method
  2014-08-08 12:30 [PATCH 1/1] net: can: sja1000: Validate initialization state in start method Mirza Krak
@ 2014-08-14 10:18 ` Marc Kleine-Budde
  2014-08-21  8:44   ` Mirza Krak
  0 siblings, 1 reply; 4+ messages in thread
From: Marc Kleine-Budde @ 2014-08-14 10:18 UTC (permalink / raw)
  To: Mirza Krak, linux-can

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On 08/08/2014 02:30 PM, Mirza Krak wrote:
> When sja1000 is not compiled as module the SJA1000 chip is only
> initialized during device registration on kernel boot. Should the chip
> get a hardware reset there is no way to reinitialize it without re-
> booting the Linux kernel.

Not good. :/

However, you can manually unbind the device from the driver:

> ➜ (pts/0) mkl@hermippe:drivers/sja1000_plx_pci ll
> total 0
> lrwxrwxrwx 1 root root    0 Aug 14 12:15 0000:01:02.0 -> ../../../../devices/pci0000:00/0000:00:1e.0/0000:01:02.0
> --w------- 1 root root 4096 Aug 14 12:15 bind
> lrwxrwxrwx 1 root root    0 Aug 14 12:15 module -> ../../../../module/plx_pci
> --w------- 1 root root 4096 Aug 14 12:15 new_id
> --w------- 1 root root 4096 Aug 14 12:15 remove_id
> --w------- 1 root root 4096 Aug 14 12:15 uevent
> --w------- 1 root root 4096 Aug 14 12:15 unbind
> ➜ (pts/0) mkl@hermippe:drivers/sja1000_plx_pci echo 0000:01:02.0 | sudo tee unbind

And then rebind it:

> ➜ (pts/0) mkl@hermippe:drivers/sja1000_plx_pci echo 0000:01:02.0 | sudo tee bind

> This patch adds a check in sja1000_start if the chip is initialized, if
> not we initialize it.

Applied to can.

Thanks,
Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH 1/1] net: can: sja1000: Validate initialization state in start method
  2014-08-14 10:18 ` Marc Kleine-Budde
@ 2014-08-21  8:44   ` Mirza Krak
  2014-08-21  9:26     ` Marc Kleine-Budde
  0 siblings, 1 reply; 4+ messages in thread
From: Mirza Krak @ 2014-08-21  8:44 UTC (permalink / raw)
  To: Marc Kleine-Budde, linux-can


On 2014-08-14 12:18, Marc Kleine-Budde wrote:
> On 08/08/2014 02:30 PM, Mirza Krak wrote:
>> When sja1000 is not compiled as module the SJA1000 chip is only
>> initialized during device registration on kernel boot. Should the chip
>> get a hardware reset there is no way to reinitialize it without re-
>> booting the Linux kernel.
> Not good. :/
>
> However, you can manually unbind the device from the driver:
>
>> ➜ (pts/0) mkl@hermippe:drivers/sja1000_plx_pci ll
>> total 0
>> lrwxrwxrwx 1 root root    0 Aug 14 12:15 0000:01:02.0 -> ../../../../devices/pci0000:00/0000:00:1e.0/0000:01:02.0
>> --w------- 1 root root 4096 Aug 14 12:15 bind
>> lrwxrwxrwx 1 root root    0 Aug 14 12:15 module -> ../../../../module/plx_pci
>> --w------- 1 root root 4096 Aug 14 12:15 new_id
>> --w------- 1 root root 4096 Aug 14 12:15 remove_id
>> --w------- 1 root root 4096 Aug 14 12:15 uevent
>> --w------- 1 root root 4096 Aug 14 12:15 unbind
>> ➜ (pts/0) mkl@hermippe:drivers/sja1000_plx_pci echo 0000:01:02.0 | sudo tee unbind
> And then rebind it:
>
>> ➜ (pts/0) mkl@hermippe:drivers/sja1000_plx_pci echo 0000:01:02.0 | sudo tee bind
Aah I see. You learn something new everyday.
>> This patch adds a check in sja1000_start if the chip is initialized, if
>> not we initialize it.
> Applied to can.
I am sorry but applied to what? I haven't seen it been applied anywhere 
when browsing linux-can on gitorious.
>
> Thanks,
> Marc
>

-- 
Med Vänliga Hälsningar / Best Regards

*******************************************************************
Mirza Krak
Host Mobility AB
mirza.krak@hostmobility.com
Anders Personsgatan 12, 416 64 Göteborg
Sweden
http://www.hostmobility.com
Direct: +46 31 31 32 704
Phone: +46 31 31 32 700
Fax: +46 31 80 67 51
Mobile: +46 730 28 06 22
*******************************************************************


^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH 1/1] net: can: sja1000: Validate initialization state in start method
  2014-08-21  8:44   ` Mirza Krak
@ 2014-08-21  9:26     ` Marc Kleine-Budde
  0 siblings, 0 replies; 4+ messages in thread
From: Marc Kleine-Budde @ 2014-08-21  9:26 UTC (permalink / raw)
  To: Mirza Krak, linux-can

[-- Attachment #1: Type: text/plain, Size: 774 bytes --]

On 08/21/2014 10:44 AM, Mirza Krak wrote:
[...]

>>> This patch adds a check in sja1000_start if the chip is initialized, if
>>> not we initialize it.
>> Applied to can.

> I am sorry but applied to what? I haven't seen it been applied anywhere
> when browsing linux-can on gitorious.

Until 5 minutes ago, it was on my hard drive only :D
But now it's included in the pull request I send to David, you can find
it on gitorious under the tag linux-can-fixes-for-3.17-20140821.

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


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^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2014-08-21  9:26 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-08-08 12:30 [PATCH 1/1] net: can: sja1000: Validate initialization state in start method Mirza Krak
2014-08-14 10:18 ` Marc Kleine-Budde
2014-08-21  8:44   ` Mirza Krak
2014-08-21  9:26     ` Marc Kleine-Budde

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