Re: problem with "serial" driver in kernel 3.16.0

From: Austin S Hemmelgarn
Date: Thu Sep 17 2015 - 16:04:13 EST


On 2015-09-17 09:24, Wolfgang Wilhelm wrote:
We are a small company FAST ComTec GmbH
(www.fastcomtec.com) and produce multichannel analyzers
with Windows software. I am the software developer and
would like to get our software working also under Linux
with the help of WINE.
Before I go any further, I would like to thank you for even considering this option. If there were more vendors who tried this, Linux would have much better support for quite a large number of hardware devices.
I was already successfull with our USB devices and most
of our PCI cards, but with one of the PCI cards
it does not work (in Debian v8, kernel 3.16.0).

Our PCI cards have a AMCC controller S5933, we use the
standard AMCC vendor id 0x10e8 and device id 0x8226,
device class serial. Most of our cards use two I/O port ranges
and an interrupt. I have written a linux driver for these cards
and could get everything working, but the interface card
for our MPA-3 multiparameter system uses only
one I/O port range and an interrupt. This card is recognized
by the "serial" driver in the kernel as a serial interface card
and there is no way to load our own driver.

My question is, could you remove in future kernel versions
the support for this card in the kernel our make it possible
to blacklist it in /etc/modprobe.d/fbdev-blacklist.conf
like other drivers that are not directly included in the kernel?
Removal is probably not an option (if there is a kernel driver for the chip already, there are almost certainly other drivers that use this chip). As far as blacklisting goes, that would be something to take up with the distribution you are developing for (so Debian from what you've said), although you may not get much help there either if the driver isn't open source. In general, it's better to either get your driver in the kernel at the source code level (which in turn includes help with ABI updates on the kernel side), or find some way to write it entirely in userspace (I'd suggest lucking at either the VFIO subsystem or the older userspace driver framework for this).

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