Re: PCI driver

[Manu Abraham <manu@kromtek.com>]

Jiri Slaby wrote:
> Manu Abraham napsal(a):
>
> > Jiri Slaby wrote:
> >
> > > Manu Abraham napsal(a):
> > >
> > > > Jiri Slaby wrote:
> > > >
> > > > > you do NOT do this at all, because you have pdev already (the param 
> > > > > of the probe function)
> > > >
> > > > I rewrote the entire thing like this including the pci_remove 
> > > > function too, but now it so seems that in the remove function, 
> > > > pci_get_drvdata(pdev) returns NULL, and hence i get an Oops at 
> > > > module removal.
> > >
> > >
> > >
> > > Maybe because this is badly written driver.
> >
> >
> >
> > I have not written the driver, but this is my first go at it ..
> >
> > > > static int mantis_pci_probe(struct pci_dev *pdev, const struct 
> > > > pci_device_id *mantis_pci_table)
> > > > {
> > > >     struct mantis_pci *mantis;
> > > >     struct mantis_eeprom eeprom;
> > > >     u8 revision, latency;
> > > >     u8 data[2];      if (pci_enable_device(pdev)) {               
> > > > dprintk(verbose, MANTIS_DEBUG, 1, "Found a mantis chip");
> > > >         if ((mantis = (struct mantis_pci *) kmalloc(sizeof (struct 
> > > > mantis_pci), GFP_KERNEL)) == NULL) {
> > > >             dprintk(verbose, MANTIS_ERROR, 1, "Out of memory");
> > > >             return -ENOMEM;
> > > >         }
> > > >         pci_set_master(pdev);
> > > >         mantis->mantis_addr = pci_resource_start(pdev, 0);
> > > >         if (!request_mem_region(pci_resource_start(pdev, 0),
> > > >             pci_resource_len(pdev, 0), DRIVER_NAME)) {
> > > >             kfree(mantis);
> > > >             return -EBUSY;
> > > >         }
> > > >         pci_read_config_byte(pdev, PCI_CLASS_REVISION, &revision);
> > > >         pci_read_config_byte(pdev, PCI_LATENCY_TIMER, &latency);
> > > >         mantis->mantis_mmio = ioremap(mantis->mantis_addr, 0x1000);
> > > >         pci_set_drvdata(pdev, mantis);       
> > >
> > >
> > >
> > > if pci_enable_device fails, you set this?? Maybe you haven't read the 
> > > doc enough.
> >
> >
> >
> >
> > I just found that, pci_enable_device() fails. So what's the way to go 
> > ahead ?
>
> JESUS.


What i meant is i do have to enable the device, not just exit.
I understood that i have to exit if pci_enable_device() fails, but what 
i am looking for is why i can't enable it in the first place.


> int retval = 0;
>
> if ((retval = pci_enable_device()))
>     goto end;
>
> ...
> pci_set_drvdata(pdev, mantis);
> ...
>
> end:
>     return retval;
>
> not
> if (pci_enable_device())
>     do something


Regards,
Manu
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