volatile variable in writing driver

[renga_murali]

what is the exact use of volatile variables in writing device drivers

Source: http://www.thescripts.com/forum/thread575614.html

[letmeknowlinux]

Normal variables { without the 'volatile' type specifier } can be stored in the cache to make the CPU access faster. There might be some situations where you don't want to cache a particular variable and you want to read the variable always from the specified location instead from cache. You declare those kind of variables as volatile.