Fan files missing in applesmc.768 (Black Macbook Santa Rosa)

[ShareBuntu]

I load applesmc on startup to adjust the fan speed through fan1_min. However, for some some reason, all the fan files have disappeared from /sys/devices/platform/applesmc.768/. Here's what I have now:



calibrate key_at_index_name subsystem temp6_input
driver key_at_index_type temp10_input temp7_input
hwmon key_count temp1_input temp8_input
input modalias temp2_input temp9_input
key_at_index name temp3_input uevent
key_at_index_data position temp4_input
key_at_index_data_length power temp5_input

Any idea how I can get it back? I added the following to /etc/rc.local:



echo 2500 > /sys/devices/platform/applesmc.768/fan1_min

Not sure if the above has anything to do with it.

[cocoon]

This happens to me as well, some of the time. I see the following pattern: if I reboot from OS X, the fan files are missing. If I do a shutdown on OS X, then boot to ubuntu, they exist. If I reboot Ubuntu, they exist.

This is a MacBook Santa Rosa, 32 bit hardy heron, and the precompiled kernel from linux-image-2.6.24-18-generic. I'm loading applesmc in /etc/modules. I'll provide more information if necessary. Right now I'm good with always doing a shutdown on OS X.

[cyberdork33]

This happens to me as well, some of the time. I see the following pattern: if I reboot from OS X, the fan files are missing. If I do a shutdown on OS X, then boot to ubuntu, they exist. If I reboot Ubuntu, they exist.

This is a MacBook Santa Rosa, 32 bit hardy heron, and the precompiled kernel from linux-image-2.6.24-18-generic. I'm loading applesmc in /etc/modules. I'll provide more information if necessary. Right now I'm good with always doing a shutdown on OS X.
there are several "variables" and such that do not get reset if you do a reboot, you have to actually powerdown the machine. The iSight firmware loading is another example.

[sands]

Does that mean, the value of fan1_min will remain 2500 after reboot?

[ShareBuntu]

Does that mean, the value of fan1_min will remain 2500 after reboot?
The applesmc.768 files will appear given that you shut down your computer completely, rather than a reboot. The best way to ensure fan1_min stays populated with the value you specified is to add an entry to /etc/rc.local; say "echo 2500 > /sys/devices/platform/applesmc.768/fan1_min" before the "exit 0" line. Negate the quotations, of course.

[dkulp]

I had the same issue of fan files not being found. Also, I couldn't get pommed to read the "light" file reliably. This is on my MacBook Pro Penryn. I was also getting a bunch of warning messages in the syslog.

I did some debugging and it looks like the applesmc needs a "retry" in it. When reading the light sensors, it would read the left sensor fine, but not read the right sensor at all. If I added a retry on the right sensor, it would read it.


I ended up modifying the applesmc.c file as:



static int __wait_status(u8 val)
{
unsigned int i;

val = val & APPLESMC_STATUS_MASK;

for (i = 0; i < 100; i++) {
if ((inb(APPLESMC_CMD_PORT) & APPLESMC_STATUS_MASK) == val) {
if (debug)
printk(KERN_DEBUG
"Waited %d us for status %x\n",
i*10, val);
return 0;
}
udelay(10);
}

/*
printk(KERN_WARNING "applesmc: wait status failed: %x != %x\n",
val, inb(APPLESMC_CMD_PORT));
*/
return -EIO;
}

/*
* applesmc_read_key - reads len bytes from a given key, and put them in buffer.
* Returns zero on success or a negative error on failure. Callers must
* hold applesmc_lock.
*/
static int applesmc_read_key(const char* key, u8* buffer, u8 len)
{
int i;

if (len > APPLESMC_MAX_DATA_LENGTH) {
printk(KERN_ERR "applesmc_read_key: cannot read more than "
"%d bytes\n", APPLESMC_MAX_DATA_LENGTH);
return -EINVAL;
}

outb(APPLESMC_READ_CMD, APPLESMC_CMD_PORT);
if (__wait_status(0x0c)) {
outb(APPLESMC_READ_CMD, APPLESMC_CMD_PORT);
if (__wait_status(0x0c)) {
return -EIO;
}
}
....... (more stuff in this method) ..........



Basically, it shortened the timeout in __wait_status and removed the printk, then added a retry in applesmc_read_key.

With that, everything seems to work fine. I can get the fans, the lights, position, etc....

Not sure why the retry is needed. Maybe the device in the newer macbooks are sending more data back or something. I don't really know.

[cyberdork33]

I ended up modifying the applesmc.c file...
You should submit these changes to the mactel-linux mailing list.