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yaml
---
r: 37258
b: refs/heads/master
c: f0cbefe
h: refs/heads/master
v: v3
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Stefan Richter authored and Ben Collins committed Jul 3, 2006
1 parent d98278c commit 04b5d74
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Showing 2 changed files with 11 additions and 22 deletions.
2 changes: 1 addition & 1 deletion [refs]
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@@ -1,2 +1,2 @@
---
refs/heads/master: 31a379e1067834868b8f1ce3e409392c42dc0f2b
refs/heads/master: f0cbefe63c4347044fffebca24c03f3c6829f322
31 changes: 10 additions & 21 deletions trunk/drivers/ieee1394/csr.c
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Expand Up @@ -17,11 +17,13 @@
*
*/

#include <linux/string.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/param.h>
#include <linux/spinlock.h>
#include <linux/string.h>

#include "csr1212.h"
#include "ieee1394_types.h"
Expand Down Expand Up @@ -149,31 +151,18 @@ static void host_reset(struct hpsb_host *host)

/*
* HI == seconds (bits 0:2)
* LO == fraction units of 1/8000 of a second, as per 1394 (bits 19:31)
*
* Convert to units and then to HZ, for comparison to jiffies.
*
* By default this will end up being 800 units, or 100ms (125usec per
* unit).
* LO == fractions of a second in units of 125usec (bits 19:31)
*
* NOTE: The spec says 1/8000, but also says we can compute based on 1/8192
* like CSR specifies. Should make our math less complex.
* Convert SPLIT_TIMEOUT to jiffies.
* The default and minimum as per 1394a-2000 clause 8.3.2.2.6 is 100ms.
*/
static inline void calculate_expire(struct csr_control *csr)
{
unsigned long units;

/* Take the seconds, and convert to units */
units = (unsigned long)(csr->split_timeout_hi & 0x07) << 13;

/* Add in the fractional units */
units += (unsigned long)(csr->split_timeout_lo >> 19);

/* Convert to jiffies */
csr->expire = (unsigned long)(units * HZ) >> 13UL;
unsigned long usecs =
(csr->split_timeout_hi & 0x07) * USEC_PER_SEC +
(csr->split_timeout_lo >> 19) * 125L;

/* Just to keep from rounding low */
csr->expire++;
csr->expire = usecs_to_jiffies(usecs > 100000L ? usecs : 100000L);

HPSB_VERBOSE("CSR: setting expire to %lu, HZ=%u", csr->expire, HZ);
}
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