On 04/26/2013 09:45 AM, Peter Hurley wrote:
On Fri, 2013-04-26 at 08:58 -0400, Mark Hounschell wrote:
On 04/25/2013 05:41 PM, Peter Hurley wrote:
On Wed, 2013-04-24 at 13:44 -0400, Mark Hounschell wrote:
I've been sort of maintaining a couple of Digi International serial port
card (XP and AP) drivers for years now because, well, they just won't do
it anymore. In any case, I'm moving from a 3.4.x kernel, that works just
fine, to a 3.8.8 kernel, that does not. I have code that does something
like this:
tty_set_operations(&SerialDriver, &SerialOps);
tty_register_driver(&SerialDriver);
maxminor = NumBoards * 64;
for (i = 0; i < maxminor; i++)
tty_register_device(&SerialDriver, i, NULL);
You're correct in diagnosing the problem to cdevs == NULL.
You're missing:
maxminor = min(num_boards * 64, 256);
serial_driver = alloc_tty_driver(maxminor);
then,
/* Fill in pertinent tty_driver fields, esp. */
serial_driver->flags = TTY_DRIVER_DYNAMIC_DEV;
tty_set_operations(serial_driver, &serial_ops);
tty_register_driver(serial_driver);
for (i = 0; i < maxminor; i++)
tty_register_device(serial_driver, i, NULL);
Thanks for responding Peter.
Earlier in the code they do this:
static struct tty_driver SerialDriver
and things like
SerialDriver.termios = kmalloc((maxminor - 256) * sizeof(TERMIOS *),
^^^^^^^^^^^^^^
is this a transcription error?
Yes, sorry. (MIN(maxminor,256) * sizeof(TERMIOS *)
GFP_KERNEL);
So is the above no longer going to work and I _must_ now use
alloc_tty_driver?
Not required but functionally equivalent. alloc_tty_driver() is actually
a wrapper macro which calls __tty_alloc_driver(). You can verify your
driver behavior against that function, if you want.
If alloc_tty_driver is now a requirement, how much is
it going to do for me? There are several things like the termios above
that are manually allocated. How much if any of this is alloc_tty_driver
going to do for me?
I can't answer this because I don't know what else your open-coded
method is doing.
Looking at __tty_alloc_driver, it looks as though only driver, cdevs and
ports are provided.
or might this work
static struct tty_driver SerialDriver
.
.
.
serial_driver.flags = TTY_DRIVER_DYNAMIC_DEV;
SerialDriver.cdevs = kcalloc(maxminor,
sizeof(SerialDriver.cdevs), GFP_KERNEL);
So might something like the above for cdevs and ports get me where I
need to be?
tty_set_operations(&serial_driver, &serial_ops);
tty_register_driver(&serial_driver);
for (i = 0; i < maxminor; i++)
tty_register_device(&serial_driver, i, NULL);
???
PS - Each board supports 64 individual serial ports??
No, this particular card comes in 4, 8, and 16 port flavors. I never did
understand why they create so many device entries. I just figured they
had a reason. For a single card, no matter how many ports, they create
64 normal serial tty entries (tty_dgdm_G0 - tty_dgdm_G63), 64 serial
printer entries (lp_dgdm_G0 - lp_dgdm_G63), and then 64 serial modem
entries (cu_dgdm_G0 - cu_dgdm_G63). Don't know why.
So where does i/o go for tty_dgdm_G16?
I have no idea. I do know that G0 - G7 are the ones I actually use for
ports 0-7 of an 8 port card-0, and
G64 - G71 are the ones I use for ports 0-7 of an 8 port card-1. I
remember long ago I had some doc explaining this but can't seem to find
it now.
Also, what host bus are these cards for?
This particular driver and one other are normal PCI based cards. I also
have one other that is PCI-e. This particular one is the only one that
creates all these weird device entries. The other 2 are pretty straight
forward. One entry per port. I figured I'd tackle this one first.
Regards
Mark
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