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Commit 9e37bc6c authored by Mirza Krak's avatar Mirza Krak Committed by Marc Kleine-Budde
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can: sja1000: Validate initialization state in start method 



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: default avatarMirza Krak <mirza.krak@hostmobility.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 02784f1b

drivers/net/can/sja1000/sja1000.c

+33 −29
Original line number Diff line number Diff line
@@ -172,6 +172,35 @@ 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);
@@ -180,6 +209,10 @@ 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);
@@ -236,35 +269,6 @@ static int sja1000_get_berr_counter(const struct net_device *dev, 
	return 0;

}



/*

 * 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: