Re: [PATCH] net: variables reach -1, but 0 tested
From: Roel Kluin <hidden>
Date: 2009-02-01 16:23:49
Also in:
lkml
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Daniel Walker wrote:
On Sat, 2009-01-31 at 11:36 +0100, Roel Kluin wrote:quoted
- while (limit--) { + while (--limit) { val = phy_read(phy, MII_BMCR); if (val >= 0 && (val & BMCR_RESET) == 0) break;It looks like these are checked for <= to 0 , are these changes strictly nessesary?
Although the chance that this goes wrong in practice is small, my change
was correct:
In the last iteration, limit is 1 when the test occurs, before the
decrement causes limit to become 0. If just then the break occurs,
we continue after the loop with:
if ((val & BMCR_ISOLATE) && limit > 0)
phy_write(phy, MII_BMCR, val & ~BMCR_ISOLATE);
return limit <= 0;
Since limit is 0, the phy_write won't occur and the return is 1, this is
not desired, I assume.
With the prefix decrement limit is always greater than 0 when the break
occurs. I do agree that the chance that this goes wrong in practice could
be small.
quoted
/* make sure EEPROM has finished loading before setting GPIO_CFG */ timeout=1000; - while ( timeout-- && (SMC_GET_E2P_CMD(lp) & E2P_CMD_EPC_BUSY_)) { + while ( --timeout && (SMC_GET_E2P_CMD(lp) & E2P_CMD_EPC_BUSY_)) { udelay(10);If your doing "timeOut" to "timeout" below may as well drop the space above after the "(" ..
Ok, here it is again:
while (timeout--) { ... }
timeout becomes -1 if the loop isn't ended otherwise, not 0.
Signed-off-by: Roel Kluin <redacted>
---
drivers/net/ibm_newemac/phy.c | 4 ++--
drivers/net/smc911x.c | 4 ++--
drivers/net/smsc9420.c | 12 ++++++------
drivers/net/sungem.c | 2 +-
drivers/net/sunqe.c | 2 +-
drivers/net/tsi108_eth.c | 2 +-
drivers/net/tulip/de2104x.c | 2 +-
7 files changed, 14 insertions(+), 14 deletions(-)
diff --git a/drivers/net/ibm_newemac/phy.c b/drivers/net/ibm_newemac/phy.c
index c40cd8d..ac9d964 100644
--- a/drivers/net/ibm_newemac/phy.c
+++ b/drivers/net/ibm_newemac/phy.c@@ -60,7 +60,7 @@ int emac_mii_reset_phy(struct mii_phy *phy) udelay(300); - while (limit--) { + while (--limit) { val = phy_read(phy, MII_BMCR); if (val >= 0 && (val & BMCR_RESET) == 0) break;
@@ -84,7 +84,7 @@ int emac_mii_reset_gpcs(struct mii_phy *phy) udelay(300); - while (limit--) { + while (--limit) { val = gpcs_phy_read(phy, MII_BMCR); if (val >= 0 && (val & BMCR_RESET) == 0) break;
diff --git a/drivers/net/smc911x.c b/drivers/net/smc911x.c
index bf3aa2a..223cde0 100644
--- a/drivers/net/smc911x.c
+++ b/drivers/net/smc911x.c@@ -220,9 +220,9 @@ static void smc911x_reset(struct net_device *dev) /* make sure EEPROM has finished loading before setting GPIO_CFG */ timeout=1000; - while ( timeout-- && (SMC_GET_E2P_CMD(lp) & E2P_CMD_EPC_BUSY_)) { + while (--timeout && (SMC_GET_E2P_CMD(lp) & E2P_CMD_EPC_BUSY_)) udelay(10); - } + if (timeout == 0){ PRINTK("%s: smc911x_reset timeout waiting for EEPROM busy\n", dev->name); return;
diff --git a/drivers/net/smsc9420.c b/drivers/net/smsc9420.c
index c14a4c6..41f5303 100644
--- a/drivers/net/smsc9420.c
+++ b/drivers/net/smsc9420.c@@ -498,7 +498,7 @@ static void smsc9420_check_mac_address(struct net_device *dev) static void smsc9420_stop_tx(struct smsc9420_pdata *pd) { u32 dmac_control, mac_cr, dma_intr_ena; - int timeOut = 1000; + int timeout = 1000; /* disable TX DMAC */ dmac_control = smsc9420_reg_read(pd, DMAC_CONTROL);
@@ -506,13 +506,13 @@ static void smsc9420_stop_tx(struct smsc9420_pdata *pd) smsc9420_reg_write(pd, DMAC_CONTROL, dmac_control); /* Wait max 10ms for transmit process to stop */ - while (timeOut--) { + while (--timeout) { if (smsc9420_reg_read(pd, DMAC_STATUS) & DMAC_STS_TS_) break; udelay(10); } - if (!timeOut) + if (!timeout) smsc_warn(IFDOWN, "TX DMAC failed to stop"); /* ACK Tx DMAC stop bit */
@@ -596,7 +596,7 @@ static void smsc9420_free_rx_ring(struct smsc9420_pdata *pd) static void smsc9420_stop_rx(struct smsc9420_pdata *pd) { - int timeOut = 1000; + int timeout = 1000; u32 mac_cr, dmac_control, dma_intr_ena; /* mask RX DMAC interrupts */
@@ -617,13 +617,13 @@ static void smsc9420_stop_rx(struct smsc9420_pdata *pd) smsc9420_pci_flush_write(pd); /* wait up to 10ms for receive to stop */ - while (timeOut--) { + while (--timeout) { if (smsc9420_reg_read(pd, DMAC_STATUS) & DMAC_STS_RS_) break; udelay(10); } - if (!timeOut) + if (!timeout) smsc_warn(IFDOWN, "RX DMAC did not stop! timeout."); /* ACK the Rx DMAC stop bit */
diff --git a/drivers/net/sungem.c b/drivers/net/sungem.c
index 86c765d..b17efa9 100644
--- a/drivers/net/sungem.c
+++ b/drivers/net/sungem.c@@ -148,7 +148,7 @@ static u16 __phy_read(struct gem *gp, int phy_addr, int reg) cmd |= (MIF_FRAME_TAMSB); writel(cmd, gp->regs + MIF_FRAME); - while (limit--) { + while (--limit) { cmd = readl(gp->regs + MIF_FRAME); if (cmd & MIF_FRAME_TALSB) break;
diff --git a/drivers/net/sunqe.c b/drivers/net/sunqe.c
index 6e8f377..fe0c3f2 100644
--- a/drivers/net/sunqe.c
+++ b/drivers/net/sunqe.c@@ -227,7 +227,7 @@ static int qe_init(struct sunqe *qep, int from_irq) if (!(sbus_readb(mregs + MREGS_PHYCONFIG) & MREGS_PHYCONFIG_LTESTDIS)) { int tries = 50; - while (tries--) { + while (--tries) { u8 tmp; mdelay(5);
diff --git a/drivers/net/tsi108_eth.c b/drivers/net/tsi108_eth.c
index 75461db..a9fd2b2 100644
--- a/drivers/net/tsi108_eth.c
+++ b/drivers/net/tsi108_eth.c@@ -1237,7 +1237,7 @@ static void tsi108_init_phy(struct net_device *dev) spin_lock_irqsave(&phy_lock, flags); tsi108_write_mii(data, MII_BMCR, BMCR_RESET); - while (i--){ + while (--i) { if(!(tsi108_read_mii(data, MII_BMCR) & BMCR_RESET)) break; udelay(10);
diff --git a/drivers/net/tulip/de2104x.c b/drivers/net/tulip/de2104x.c
index d5d53b6..0bf2114 100644
--- a/drivers/net/tulip/de2104x.c
+++ b/drivers/net/tulip/de2104x.c@@ -392,7 +392,7 @@ static void de_rx (struct de_private *de) unsigned drop = 0; int rc; - while (rx_work--) { + while (--rx_work) { u32 status, len; dma_addr_t mapping; struct sk_buff *skb, *copy_skb;