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>
diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
index ee13dc7..3e34187 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.c
+++ b/drivers/net/ethernet/ti/davinci_cpdma.c
@@ -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 @@
}
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 @@
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 @@
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 */