= Over 80-character line tips =

== Breaking comment lines ==
When breaking up comment lines that are over 80-characters, make sure to use the correct multi-line comment style, which is either:

{{{
        /* One line.
         * Two lines.
         */
}}}
or
{{{
        /*
         * One line
         * Two lines.
         */

}}}

Different driver authors use different styles, so use the style that is most common in the driver.

== Breaking function calls ==
Sometimes a call to a function has several variables, and you need to break the line in the middle of those variables.  Look at this example:

{{{
        pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN, GFP_KERNEL, &pdata->urb->transfer_dma);
}}}

This line is too long, so we want to break it up.  By default, vim will increase the indentation of the trailing line by one tab:

{{{
        pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
                GFP_KERNEL, &pdata->urb->transfer_dma);
}}}

This style is fine, and generally perferred.  However, some driver writers prefer to have the trailing line of a function call line up with the starting '('.  They use tabs, followed by spaces, to align the trailing line:

{{{
        pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
                                            GFP_KERNEL,
                                            &pdata->urb->transfer_dma);
}}}

Again, the one tab indent style is preferred, but don't change lines that use the other style.

== Breaking long math lines ==

When breaking up long math lines, make sure to break after an operator, like this:
{{{
        really_long_function_call(other_long_function_call(variable) &&
                        yet_another_long_function_call(variable));
}}}

= Parens in return value =

Ignore checkpatch.pl if it complains about parens around boolean expressions or ternary conditionals in return values, like this:
{{{
        return ((depth > 1) ? (depth - 1) : depth);
}}}