Re: [PATCH 1/2] misc: add CARMA DATA-FPGA Access Driver

On Wed, Feb 09, 2011 at 10:27:40AM -0800, Dmitry Torokhov wrote:

[ snip stuff I've already fixed in the next version ]

quoted

The requirement is that the device stay open during reconfiguration.
This provides for that. Readers just block for as long as the device is
not producing data.

OK, you still need to make sure you do not touch free/used buffer while
device is disabled. Also, you need to kick readers if you unbind the
driver, so maybe a new flag priv->exists should be introduced and
checked.

I don't understand what you mean by "kick readers if you unbind the
driver". The kernel automatically increases the refcount on a module
when a process is using the module. This shows up in the "Used by"
column of lsmod's output.

The kernel will not let you rmmod a module with a non-zero refcount. You
cannot get into the situation where you have rmmod'ed the module and a
reader is still blocking in read()/poll().

Thanks for the review. A v6 is coming right up.

Ira