2014-12-14 08:34:27

by Asaf Vertz

[permalink] [raw]
Subject: [PATCH] cirrus: cs89x0: fix time comparison

To be future-proof and for better readability the time comparisons are
modified to use time_before, time_after, and time_after_eq instead of
plain, error-prone math.

Signed-off-by: Asaf Vertz <[email protected]>
---
drivers/net/ethernet/cirrus/cs89x0.c | 27 ++++++++++++++-------------
1 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/cirrus/cs89x0.c b/drivers/net/ethernet/cirrus/cs89x0.c
index 9823a0e..965331f 100644
--- a/drivers/net/ethernet/cirrus/cs89x0.c
+++ b/drivers/net/ethernet/cirrus/cs89x0.c
@@ -60,6 +60,7 @@
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
+#include <linux/jiffies.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/string.h>
@@ -238,13 +239,13 @@ writereg(struct net_device *dev, u16 regno, u16 value)
static int __init
wait_eeprom_ready(struct net_device *dev)
{
- int timeout = jiffies;
+ unsigned long timeout = jiffies;
/* check to see if the EEPROM is ready,
* a timeout is used just in case EEPROM is ready when
* SI_BUSY in the PP_SelfST is clear
*/
while (readreg(dev, PP_SelfST) & SI_BUSY)
- if (jiffies - timeout >= 40)
+ if (time_after_eq(jiffies, timeout + 40))
return -1;
return 0;
}
@@ -485,7 +486,7 @@ control_dc_dc(struct net_device *dev, int on_not_off)
{
struct net_local *lp = netdev_priv(dev);
unsigned int selfcontrol;
- int timenow = jiffies;
+ unsigned long timenow = jiffies;
/* control the DC to DC convertor in the SelfControl register.
* Note: This is hooked up to a general purpose pin, might not
* always be a DC to DC convertor.
@@ -499,7 +500,7 @@ control_dc_dc(struct net_device *dev, int on_not_off)
writereg(dev, PP_SelfCTL, selfcontrol);

/* Wait for the DC/DC converter to power up - 500ms */
- while (jiffies - timenow < HZ)
+ while (time_before(jiffies, timenow + HZ))
;
}

@@ -514,7 +515,7 @@ send_test_pkt(struct net_device *dev)
0, 0, /* DSAP=0 & SSAP=0 fields */
0xf3, 0 /* Control (Test Req + P bit set) */
};
- long timenow = jiffies;
+ unsigned long timenow = jiffies;

writereg(dev, PP_LineCTL, readreg(dev, PP_LineCTL) | SERIAL_TX_ON);

@@ -525,10 +526,10 @@ send_test_pkt(struct net_device *dev)
iowrite16(ETH_ZLEN, lp->virt_addr + TX_LEN_PORT);

/* Test to see if the chip has allocated memory for the packet */
- while (jiffies - timenow < 5)
+ while (time_before(jiffies, timenow + 5))
if (readreg(dev, PP_BusST) & READY_FOR_TX_NOW)
break;
- if (jiffies - timenow >= 5)
+ if (time_after_eq(jiffies, timenow + 5))
return 0; /* this shouldn't happen */

/* Write the contents of the packet */
@@ -536,7 +537,7 @@ send_test_pkt(struct net_device *dev)

cs89_dbg(1, debug, "Sending test packet ");
/* wait a couple of jiffies for packet to be received */
- for (timenow = jiffies; jiffies - timenow < 3;)
+ for (timenow = jiffies; time_before(jiffies, timenow + 3);)
;
if ((readreg(dev, PP_TxEvent) & TX_SEND_OK_BITS) == TX_OK) {
cs89_dbg(1, cont, "succeeded\n");
@@ -556,7 +557,7 @@ static int
detect_tp(struct net_device *dev)
{
struct net_local *lp = netdev_priv(dev);
- int timenow = jiffies;
+ unsigned long timenow = jiffies;
int fdx;

cs89_dbg(1, debug, "%s: Attempting TP\n", dev->name);
@@ -574,7 +575,7 @@ detect_tp(struct net_device *dev)
/* Delay for the hardware to work out if the TP cable is present
* - 150ms
*/
- for (timenow = jiffies; jiffies - timenow < 15;)
+ for (timenow = jiffies; time_before(jiffies, timenow + 15);)
;
if ((readreg(dev, PP_LineST) & LINK_OK) == 0)
return DETECTED_NONE;
@@ -618,7 +619,7 @@ detect_tp(struct net_device *dev)
if ((lp->auto_neg_cnf & AUTO_NEG_BITS) == AUTO_NEG_ENABLE) {
pr_info("%s: negotiating duplex...\n", dev->name);
while (readreg(dev, PP_AutoNegST) & AUTO_NEG_BUSY) {
- if (jiffies - timenow > 4000) {
+ if (time_after(jiffies, timenow + 4000)) {
pr_err("**** Full / half duplex auto-negotiation timed out ****\n");
break;
}
@@ -1271,7 +1272,7 @@ static void __init reset_chip(struct net_device *dev)
{
#if !defined(CONFIG_MACH_MX31ADS)
struct net_local *lp = netdev_priv(dev);
- int reset_start_time;
+ unsigned long reset_start_time;

writereg(dev, PP_SelfCTL, readreg(dev, PP_SelfCTL) | POWER_ON_RESET);

@@ -1294,7 +1295,7 @@ static void __init reset_chip(struct net_device *dev)
/* Wait until the chip is reset */
reset_start_time = jiffies;
while ((readreg(dev, PP_SelfST) & INIT_DONE) == 0 &&
- jiffies - reset_start_time < 2)
+ time_before(jiffies, reset_start_time + 2))
;
#endif /* !CONFIG_MACH_MX31ADS */
}
--
1.7.0.4


2014-12-15 16:44:47

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] cirrus: cs89x0: fix time comparison

From: Asaf Vertz <[email protected]>
Date: Sun, 14 Dec 2014 10:34:18 +0200

> To be future-proof and for better readability the time comparisons are
> modified to use time_before, time_after, and time_after_eq instead of
> plain, error-prone math.
>
> Signed-off-by: Asaf Vertz <[email protected]>

Applied.