((thermometer < 0) ? 0 : (thermometer == X)) and (thermometer == X) are equal for X >= 0.
Signed-off-by: Ivan Safonov <[email protected]>
---
drivers/net/wireless/ath/ath9k/ar9003_eeprom.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
index 8b4561e..35e57f7 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
@@ -4097,16 +4097,16 @@ static void ar9003_hw_thermometer_apply(struct ath_hw *ah)
REG_RMW_FIELD(ah, AR_PHY_65NM_CH2_RXTX4,
AR_PHY_65NM_CH0_RXTX4_THERM_ON_OVR, therm_on);
- therm_on = (thermometer < 0) ? 0 : (thermometer == 0);
+ therm_on = thermometer == 0;
REG_RMW_FIELD(ah, AR_PHY_65NM_CH0_RXTX4,
AR_PHY_65NM_CH0_RXTX4_THERM_ON, therm_on);
if (pCap->chip_chainmask & BIT(1)) {
- therm_on = (thermometer < 0) ? 0 : (thermometer == 1);
+ therm_on = thermometer == 1;
REG_RMW_FIELD(ah, AR_PHY_65NM_CH1_RXTX4,
AR_PHY_65NM_CH0_RXTX4_THERM_ON, therm_on);
}
if (pCap->chip_chainmask & BIT(2)) {
- therm_on = (thermometer < 0) ? 0 : (thermometer == 2);
+ therm_on = thermometer == 2;
REG_RMW_FIELD(ah, AR_PHY_65NM_CH2_RXTX4,
AR_PHY_65NM_CH0_RXTX4_THERM_ON, therm_on);
}
--
2.4.10
On Mon, 2015-12-28 at 20:48 +0700, Ivan Safonov wrote:
> ((thermometer < 0) ? 0 : (thermometer == X)) and (thermometer == X) are equal for X >= 0.
X is not guaranteed to be >= 0 here
> Signed-off-by: Ivan Safonov <[email protected]>
> ---
> ?drivers/net/wireless/ath/ath9k/ar9003_eeprom.c | 6 +++---
> ?1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
[]
> @@ -4097,16 +4097,16 @@ static void ar9003_hw_thermometer_apply(struct ath_hw *ah)
> ? REG_RMW_FIELD(ah, AR_PHY_65NM_CH2_RXTX4,
> ? ??????AR_PHY_65NM_CH0_RXTX4_THERM_ON_OVR, therm_on);
> ?
> - therm_on = (thermometer < 0) ? 0 : (thermometer == 0);
> + therm_on = thermometer == 0;
This code is not equivalent.
Check what happens when thermometer is -1.
> ? REG_RMW_FIELD(ah, AR_PHY_65NM_CH0_RXTX4,
> ? ??????AR_PHY_65NM_CH0_RXTX4_THERM_ON, therm_on);
> ? if (pCap->chip_chainmask & BIT(1)) {
> - therm_on = (thermometer < 0) ? 0 : (thermometer == 1);
> + therm_on = thermometer == 1;
> ? REG_RMW_FIELD(ah, AR_PHY_65NM_CH1_RXTX4,
> ? ??????AR_PHY_65NM_CH0_RXTX4_THERM_ON, therm_on);
> ? }
> ? if (pCap->chip_chainmask & BIT(2)) {
> - therm_on = (thermometer < 0) ? 0 : (thermometer == 2);
> + therm_on = thermometer == 2;
> ? REG_RMW_FIELD(ah, AR_PHY_65NM_CH2_RXTX4,
> ? ??????AR_PHY_65NM_CH0_RXTX4_THERM_ON, therm_on);
> ? }
On Tue, 2015-12-29 at 01:38 +0700, Ivan Safonov wrote:
> On 12/29/2015 12:56 AM, Joe Perches wrote:
> > On Mon, 2015-12-28 at 20:48 +0700, Ivan Safonov wrote:
> > > ((thermometer < 0) ? 0 : (thermometer == X)) and (thermometer ==
> > > X) are equal for X >= 0.
> > X is not guaranteed to be >= 0 here
>
> X is fixed constant. In this case X is {0, 1, 2}.
Looks like it can be -1 to me (range: -1, 0, 1, 2)
static int ar9003_hw_get_thermometer(struct ath_hw *ah)
{
struct ar9300_eeprom *eep = &ah->eeprom.ar9300_eep;
struct ar9300_base_eep_hdr *pBase = &eep->baseEepHeader;
int thermometer =??(pBase->miscConfiguration >> 1) & 0x3;
return --thermometer;
}
On 12/29/2015 07:31 AM, Joe Perches wrote:
> On Tue, 2015-12-29 at 01:38 +0700, Ivan Safonov wrote:
>> On 12/29/2015 12:56 AM, Joe Perches wrote:
>>> On Mon, 2015-12-28 at 20:48 +0700, Ivan Safonov wrote:
>>>> ((thermometer < 0) ? 0 : (thermometer == X)) and (thermometer ==
>>>> X) are equal for X >= 0.
>>> X is not guaranteed to be >= 0 here
>> X is fixed constant. In this case X is {0, 1, 2}.
> Looks like it can be -1 to me (range: -1, 0, 1, 2)
>
> static int ar9003_hw_get_thermometer(struct ath_hw *ah)
> {
> struct ar9300_eeprom *eep = &ah->eeprom.ar9300_eep;
> struct ar9300_base_eep_hdr *pBase = &eep->baseEepHeader;
> int thermometer = (pBase->miscConfiguration >> 1) & 0x3;
>
> return --thermometer;
> }
X is not thermometer. The thermometer is {-1, 0, 1, 2}. X is {0, 1, 2}.
All possible X valueswritten in the comments:
ar9003_hw_get_thermometer used only in ar9003_hw_thermometer_apply:
static void ar9003_hw_thermometer_apply(struct ath_hw *ah)
{
struct ath9k_hw_capabilities *pCap = &ah->caps;
int thermometer = ar9003_hw_get_thermometer(ah);
u8 therm_on = (thermometer < 0) ? 0 : 1;
REG_RMW_FIELD(ah, AR_PHY_65NM_CH0_RXTX4,
AR_PHY_65NM_CH0_RXTX4_THERM_ON_OVR, therm_on);
if (pCap->chip_chainmask & BIT(1))
REG_RMW_FIELD(ah, AR_PHY_65NM_CH1_RXTX4,
AR_PHY_65NM_CH0_RXTX4_THERM_ON_OVR, therm_on);
if (pCap->chip_chainmask & BIT(2))
REG_RMW_FIELD(ah, AR_PHY_65NM_CH2_RXTX4,
AR_PHY_65NM_CH0_RXTX4_THERM_ON_OVR, therm_on);
therm_on = (thermometer < 0) ? 0 : (thermometer == 0); /* X = 0 */
REG_RMW_FIELD(ah, AR_PHY_65NM_CH0_RXTX4,
AR_PHY_65NM_CH0_RXTX4_THERM_ON, therm_on);
if (pCap->chip_chainmask & BIT(1)) {
therm_on = (thermometer < 0) ? 0 : (thermometer == 1);
/* X = 1 */
REG_RMW_FIELD(ah, AR_PHY_65NM_CH1_RXTX4,
AR_PHY_65NM_CH0_RXTX4_THERM_ON, therm_on);
}
if (pCap->chip_chainmask & BIT(2)) {
therm_on = (thermometer < 0) ? 0 : (thermometer == 2);
/* X = 2 */
REG_RMW_FIELD(ah, AR_PHY_65NM_CH2_RXTX4,
AR_PHY_65NM_CH0_RXTX4_THERM_ON, therm_on);
}
}
There is no X = -1.
On 12/29/2015 12:56 AM, Joe Perches wrote:
> On Mon, 2015-12-28 at 20:48 +0700, Ivan Safonov wrote:
>> ((thermometer < 0) ? 0 : (thermometer == X)) and (thermometer == X) are equal for X >= 0.
> X is not guaranteed to be >= 0 here
X is fixed constant. In this case X is {0, 1, 2}.
>> @@ -4097,16 +4097,16 @@ static void ar9003_hw_thermometer_apply(struct ath_hw *ah)
>> REG_RMW_FIELD(ah, AR_PHY_65NM_CH2_RXTX4,
>> AR_PHY_65NM_CH0_RXTX4_THERM_ON_OVR, therm_on);
>>
>> - therm_on = (thermometer < 0) ? 0 : (thermometer == 0);
>> + therm_on = thermometer == 0;
> This code is not equivalent.
>
> Check what happens when thermometer is -1.
therm_on = (thermometer < 0) ? 0 : (thermometer == 0) =>
therm_on = (true) ? 0 : (thermometer == 0) =>
therm_on is 0
therm_on = thermometer == 0 =>
therm_on = false
false is equal to 0
Value of the thermometer variable isanerror code, or athermometercode.
The thermometercode is never equal to the error code (thermometercode >=
0, error code <0).