Some Questions

[Yong Ma]

----- Original Message -----
From: "John Baldwin" <jhb at freebsd.org>
To: freebsd-drivers at freebsd.org
Subject: Re: Some Questions
Date: Tue, 18 Oct 2005 11:17:51 -0400

> 
> On Tuesday 18 October 2005 04:26 am, Yong Ma wrote:
> > Hi everybody:
> >
> >
> > I'm new here,nice to meet you all! I'm also aFreeBSD_device_driver newbie,
> > and now I'm enaged in writting a driverfor a cryptographic accelerator
> > card.As a preparation I read thesections of device driver in "FreeBSD
> > Architecture Handbook",andexercised the example driver in the book.now I
> > have several questions(maybeeasy for you but most useful for me):
> >
> > 1)Some drivers declares the device_open() as int device_open(dev_t
> > dev,...),and some declare it as int device_open(struct cdev
> > *dev,...),sometimes the first one couldn't be compliedsuccessfully,what's
> > the difference?
> 
> On 6.0 and later you should use 'struct cdev *dev' and on 5.x and earlier
> 'dev_t dev'.
> 
> > 2) if (pci_get_vendor(dev) == 0x11c1) { ...
> >                               ~~~~~~~~how to get this number if I don't
> > know it?
> 
> This number is part of the chip ID in pciconf -l output.  For example, on my
> laptop:
> 
> pcib1 at pci0:1:0: class=0x060400 card=0x00000000 chip=0x1a318086 rev=0x04
> hdr=0x01
> 
> For this device, pci_get_devid(dev) would return 0x1a318086.
> pci_get_vendor(dev) would return the 0x8086 part of that.
> 
> > 3)Could the device on PCI slot be listed by /pciconf -l /without driver.
> 
> You mean cutting out the pcib1 part from the line above?  You could always use
> something like awk, sed, or cut.  For example:
> 
> % pciconf -l | cut -d @ -f 2
> pci0:0:0:       class=0x060000 card=0x56001558 chip=0x1a308086 rev=0x04
> hdr=0x00
> pci0:1:0:       class=0x060400 card=0x00000000 chip=0x1a318086 rev=0x04
> hdr=0x01
> pci0:29:0:      class=0x0c0300 card=0x56001558 chip=0x24828086 rev=0x02
> hdr=0x00
> ...
> 
> > 4)The printf() seems not work under XWindow mode in functions like
> > deviec_prob or device_attach,how to make it work?
> 
> Run 'dmesg' in your Xterminal to see the messages.  Alternatively, you can use
> the 'xconsole' program which should show the messages in its window.
> 
> > 5)If only the pseudo-device in /dev can be destroyed with
> > destroy_dev(sc->dev0) in detach() function in a KLD driver? I can't do
> > that!
> 
> I'm not sure what you are asking here.  You can't leave an entry in /dev
> around when your module is unloaded via kldunload since you would be removing
> the devsw and devsw functions that back that device resulting in a kernel
> panic the next time some process tried to use the /dev entry.  What exact
> problem are you trying to solve?
> 
There is a make_dev() in the attach() in my test driver,and a destroy_dev() and a bus_generic_detach() in the detach(),but the later ones seems don't work when I unload the KLD module,while the make_dev() works properly,so as I load and unload the module,there are quite a few devices in /dev have the same name(for me they are mypci0).
Several days ago,I did a driver test of a PSEUDO-DEVICE with the detach() works properly.I wander if it is because of the real HARDWARE device this time ?

this is my detach() function:

static int
mypci_detach(device_t dev)
{

    struct mypci_softc *sc;
    sc = (struct mypci_softc *) device_get_softc(dev);
    destroy_dev(sc->dev0);
    bus_generic_detach(dev);
    bus_release_resource(dev, SYS_RES_IOPORT, sc->rid, sc->res);
    printf("Mypci detached!\n");
    return (0);
}
> --
> John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
> "Power Users Use the Power to Serve"  =  http://www.FreeBSD.org

Thanks very much

Yong

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