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net/davinci_cpdma: don't check for jiffies with interrupts 

__cpdma_chan_process() holds the lock with interrupts off (and its
caller as well), same goes for cpdma_ctlr_start(). With interrupts off,
jiffies will not make any progress and if the wait condition never gets
true we wait for ever.
Tgis patch adds a a simple udelay and counting down attempt.

Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sebastian Siewior 2013-04-23 07:31:35 +00:00 committed by David S. Miller
parent 2bac7cb316
commit 817f6d1a13
1 changed files with 12 additions and 8 deletions
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20
drivers/net/ethernet/ti/davinci_cpdma.c
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@ -20,6 +20,7 @@
#include <linux/err.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/delay.h>
#include "davinci_cpdma.h"
@ -312,14 +313,16 @@ int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
}
if (ctlr->params.has_soft_reset) {
unsigned long timeout = jiffies + HZ/10;
unsigned timeout = 10 * 100;
dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
while (time_before(jiffies, timeout)) {
while (timeout) {
if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
break;
udelay(10);
timeout--;
}
WARN_ON(!time_before(jiffies, timeout));
WARN_ON(!timeout);
}
for (i = 0; i < ctlr->num_chan; i++) {
@ -868,7 +871,7 @@ int cpdma_chan_stop(struct cpdma_chan *chan)
struct cpdma_desc_pool *pool = ctlr->pool;
unsigned long flags;
int ret;
unsigned long timeout;
unsigned timeout;
spin_lock_irqsave(&chan->lock, flags);
if (chan->state != CPDMA_STATE_ACTIVE) {
@ -883,14 +886,15 @@ int cpdma_chan_stop(struct cpdma_chan *chan)
dma_reg_write(ctlr, chan->td, chan_linear(chan));
/* wait for teardown complete */
timeout = jiffies + HZ/10; /* 100 msec */
while (time_before(jiffies, timeout)) {
timeout = 100 * 100; /* 100 ms */
while (timeout) {
u32 cp = chan_read(chan, cp);
if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
break;
cpu_relax();
udelay(10);
timeout--;
}
WARN_ON(!time_before(jiffies, timeout));
WARN_ON(!timeout);
chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
/* handle completed packets */