[alsa-devel] [patch] ALSA: es1968: precedence bug in snd_es1968_tea575x_get_pins()
I don't think this works as intended. '|' higher precedence than ?: so the bitwize OR "0 | (val & STR_MOST)" is a no-op.
I have re-written it to be more clear.
Signed-off-by: Dan Carpenter dan.carpenter@oracle.com --- I don't have a way to test this.
diff --git a/sound/pci/es1968.c b/sound/pci/es1968.c index 50169bc..7266020 100644 --- a/sound/pci/es1968.c +++ b/sound/pci/es1968.c @@ -2581,9 +2581,14 @@ static u8 snd_es1968_tea575x_get_pins(struct snd_tea575x *tea) struct es1968 *chip = tea->private_data; unsigned long io = chip->io_port + GPIO_DATA; u16 val = inw(io); - - return (val & STR_DATA) ? TEA575X_DATA : 0 | - (val & STR_MOST) ? TEA575X_MOST : 0; + u8 ret; + + ret = 0; + if (val & STR_DATA) + ret |= TEA575X_DATA; + if (val & STR_MOST) + ret |= TEA575X_MOST; + return ret; }
static void snd_es1968_tea575x_set_direction(struct snd_tea575x *tea, bool output)
At Tue, 13 Nov 2012 10:44:54 +0300, Dan Carpenter wrote:
I don't think this works as intended. '|' higher precedence than ?: so the bitwize OR "0 | (val & STR_MOST)" is a no-op.
I have re-written it to be more clear.
Signed-off-by: Dan Carpenter dan.carpenter@oracle.com
Thanks, applied now.
Takashi
I don't have a way to test this.
diff --git a/sound/pci/es1968.c b/sound/pci/es1968.c index 50169bc..7266020 100644 --- a/sound/pci/es1968.c +++ b/sound/pci/es1968.c @@ -2581,9 +2581,14 @@ static u8 snd_es1968_tea575x_get_pins(struct snd_tea575x *tea) struct es1968 *chip = tea->private_data; unsigned long io = chip->io_port + GPIO_DATA; u16 val = inw(io);
- return (val & STR_DATA) ? TEA575X_DATA : 0 |
(val & STR_MOST) ? TEA575X_MOST : 0;
- u8 ret;
- ret = 0;
- if (val & STR_DATA)
ret |= TEA575X_DATA;- if (val & STR_MOST)
ret |= TEA575X_MOST;- return ret;
}
static void snd_es1968_tea575x_set_direction(struct snd_tea575x *tea, bool output)
On Tue, 2012-11-13 at 10:44 +0300, Dan Carpenter wrote:
I don't think this works as intended. '|' higher precedence than ?: so the bitwize OR "0 | (val & STR_MOST)" is a no-op.
I have re-written it to be more clear.
[]
diff --git a/sound/pci/es1968.c b/sound/pci/es1968.c
[]
@@ -2581,9 +2581,14 @@ static u8 snd_es1968_tea575x_get_pins(struct snd_tea575x *tea) struct es1968 *chip = tea->private_data; unsigned long io = chip->io_port + GPIO_DATA; u16 val = inw(io);
- return (val & STR_DATA) ? TEA575X_DATA : 0 |
(val & STR_MOST) ? TEA575X_MOST : 0;
- u8 ret;
- ret = 0;
- if (val & STR_DATA)
ret |= TEA575X_DATA;- if (val & STR_MOST)
ret |= TEA575X_MOST;- return ret;
Cute. smatch I presume? Tools are useful.
Moving the close parentheses is a pretty common style too
return (val & STR_DATA ? TEA575X_DATA : 0) | (val & STR_MOST ? TEA575X_MOST : 0);
On Tue, Nov 13, 2012 at 12:03:10AM -0800, Joe Perches wrote:
On Tue, 2012-11-13 at 10:44 +0300, Dan Carpenter wrote:
I don't think this works as intended. '|' higher precedence than ?: so the bitwize OR "0 | (val & STR_MOST)" is a no-op.
I have re-written it to be more clear.
[]
diff --git a/sound/pci/es1968.c b/sound/pci/es1968.c
[]
@@ -2581,9 +2581,14 @@ static u8 snd_es1968_tea575x_get_pins(struct snd_tea575x *tea) struct es1968 *chip = tea->private_data; unsigned long io = chip->io_port + GPIO_DATA; u16 val = inw(io);
- return (val & STR_DATA) ? TEA575X_DATA : 0 |
(val & STR_MOST) ? TEA575X_MOST : 0;
- u8 ret;
- ret = 0;
- if (val & STR_DATA)
ret |= TEA575X_DATA;- if (val & STR_MOST)
ret |= TEA575X_MOST;- return ret;
Cute. smatch I presume? Tools are useful.
Yep. This is a smatch thing.
Moving the close parentheses is a pretty common style too
return (val & STR_DATA ? TEA575X_DATA : 0) | (val & STR_MOST ? TEA575X_MOST : 0);
That would work as well, of course. I don't have a strong preference either way.
regards, dan carpenter
On Tuesday 13 November 2012 08:44:54 Dan Carpenter wrote:
I don't think this works as intended. '|' higher precedence than ?: so the bitwize OR "0 | (val & STR_MOST)" is a no-op.
I have re-written it to be more clear.
Signed-off-by: Dan Carpenter dan.carpenter@oracle.com
I don't have a way to test this.
Thanks for the patch. I tested it and it works.
The same way as without the patch...weird. DATA pin reading works because that's required for the chip detection. Stereo indication (MOST pin) works too.
diff --git a/sound/pci/es1968.c b/sound/pci/es1968.c index 50169bc..7266020 100644 --- a/sound/pci/es1968.c +++ b/sound/pci/es1968.c @@ -2581,9 +2581,14 @@ static u8 snd_es1968_tea575x_get_pins(struct snd_tea575x *tea) struct es1968 *chip = tea->private_data; unsigned long io = chip->io_port + GPIO_DATA; u16 val = inw(io);
- return (val & STR_DATA) ? TEA575X_DATA : 0 |
(val & STR_MOST) ? TEA575X_MOST : 0;
- u8 ret;
- ret = 0;
- if (val & STR_DATA)
ret |= TEA575X_DATA;- if (val & STR_MOST)
ret |= TEA575X_MOST;- return ret;
}
static void snd_es1968_tea575x_set_direction(struct snd_tea575x *tea, bool output) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
participants (4)
-
Dan Carpenter -
Joe Perches -
Ondrej Zary -
Takashi Iwai