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Commit 26ac14e2 authored by Oliver Endriss's avatar Oliver Endriss Committed by Mauro Carvalho Chehab
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V4L/DVB (6495): saa7146: saa7146_wait_for_debi_done fixes 



Two fixes for the 'saa7146_wait_for_debi_done' code:
(a) Timeout did not work when the routine was called with
    interrupts disabled.
(b) Reduce PCI I/O load caused by saa7146_wait_for_debi_done.
    Seems to be very important on fast machines!

Based on code posted by Hartmut Birr @vdr-portal.


Signed-off-by: default avatarOliver Endriss <o.endriss@gmx.de>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@infradead.org>
parent cb20630c

drivers/media/common/saa7146_core.c

+58 −12
Original line number Original line Diff line number Diff line
@@ -59,43 +59,89 @@ void saa7146_setgpio(struct saa7146_dev *dev, int port, u32 data) 
}

}





/* This DEBI code is based on the saa7146 Stradis driver by Nathan Laredo */

/* This DEBI code is based on the saa7146 Stradis driver by Nathan Laredo */

int saa7146_wait_for_debi_done(struct saa7146_dev *dev, int nobusyloop)

static inline int saa7146_wait_for_debi_done_sleep(struct saa7146_dev *dev,

				unsigned long us1, unsigned long us2)

{

{

	unsigned long start;

	unsigned long timeout;

	int err;

	int err;





	/* wait for registers to be programmed */

	/* wait for registers to be programmed */

	start = jiffies;

	timeout = jiffies + usecs_to_jiffies(us1);

	while (1) {

	while (1) {

		err = time_after(jiffies, start + HZ/20);

		err = time_after(jiffies, timeout);

		if (saa7146_read(dev, MC2) & 2)

		if (saa7146_read(dev, MC2) & 2)

			break;

			break;

		if (err) {

		if (err) {

			DEB_S(("timed out while waiting for registers getting programmed\n"));

			printk(KERN_ERR "%s: %s timed out while waiting for "

					"registers getting programmed\n",

					dev->name, __FUNCTION__);

			return -ETIMEDOUT;

			return -ETIMEDOUT;

		}

		}

		if (nobusyloop)

		msleep(1);

		msleep(1);

	}

	}





	/* wait for transfer to complete */

	/* wait for transfer to complete */

	start = jiffies;

	timeout = jiffies + usecs_to_jiffies(us2);

	while (1) {

	while (1) {

		err = time_after(jiffies, start + HZ/4);

		err = time_after(jiffies, timeout);

		if (!(saa7146_read(dev, PSR) & SPCI_DEBI_S))

		if (!(saa7146_read(dev, PSR) & SPCI_DEBI_S))

			break;

			break;

		saa7146_read(dev, MC2);

		saa7146_read(dev, MC2);

		if (err) {

		if (err) {

			DEB_S(("timed out while waiting for transfer completion\n"));

			DEB_S(("%s: %s timed out while waiting for transfer "

				"completion\n",	dev->name, __FUNCTION__));

			return -ETIMEDOUT;

			return -ETIMEDOUT;

		}

		}

		if (nobusyloop)

		msleep(1);

		msleep(1);

	}

	}





	return 0;

	return 0;

}

}





static inline int saa7146_wait_for_debi_done_busyloop(struct saa7146_dev *dev,

				unsigned long us1, unsigned long us2)

{

	unsigned long loops;



	/* wait for registers to be programmed */

	loops = us1;

	while (1) {

		if (saa7146_read(dev, MC2) & 2)

			break;

		if (!loops--) {

			printk(KERN_ERR "%s: %s timed out while waiting for "

					"registers getting programmed\n",

					dev->name, __FUNCTION__);

			return -ETIMEDOUT;

		}

		udelay(1);

	}



	/* wait for transfer to complete */

	loops = us2 / 5;

	while (1) {

		if (!(saa7146_read(dev, PSR) & SPCI_DEBI_S))

			break;

		saa7146_read(dev, MC2);

		if (!loops--) {

			DEB_S(("%s: %s timed out while waiting for transfer "

				"completion\n", dev->name, __FUNCTION__));

			return -ETIMEDOUT;

		}

		udelay(5);

	}



	return 0;

}



int saa7146_wait_for_debi_done(struct saa7146_dev *dev, int nobusyloop)

{

	if (nobusyloop)

		return saa7146_wait_for_debi_done_sleep(dev, 50000, 250000);

	else

		return saa7146_wait_for_debi_done_busyloop(dev, 50000, 250000);

}



/****************************************************************************

/****************************************************************************

 * general helper functions

 * general helper functions

 ****************************************************************************/

 ****************************************************************************/