Manu Abraham wrote:I am in fact doing that ..
Jiri Slaby wrote:
Manu Abraham napsal(a):Hmm.. i finally got it to work. It seems pci_get_device() is necessary,
Jiri Slaby wrote:JESUS.
Manu Abraham napsal(a):I just found that, pci_enable_device() fails. So what's the way to go
Jiri Slaby wrote:
you do NOT do this at all, because you have pdev already (the paramI rewrote the entire thing like this including the pci_remove
of the probe function)
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.
ahead ?
i can't seem to enable the device or request for an IRQ the way you
suggested. It looks some quirks are there though ..
If only i could explain why it works this way and not the other way ..
Because pci_enable_device() works like most other kernel (and also libc) functions: it returns 0 if everything went fine.
[ 81.269655] mantis_pci_probe: Got a device
[ 81.269825] mantis_pci_probe: We got an IRQ
[ 81.269987] mantis_pci_probe: We finally enabled the device
[ 81.270191] Mantis Rev 1, irq: 23, latency: 32
[ 81.270289] memory: 0xefeff000, mmio: f9218000
[ 81.270519] Trying to free free IRQ23
[ 90.485885] mantis_pci_remove: Removing -->Mantis irq: 23, latency: 32
[ 90.485887] memory: 0xefeff000, mmio: 0xf9218000
[ 90.486293] Trying to free free IRQ23
[ 90.486429] Trying to free nonexistent resource <efeff000-efefffff>
You should introduce a table of PCI devices here that your driver feels responsible for. Then put this into a struct pci_driver which you pass to
pci_module_init. Take a look on a random other PCI driver, drivers/net/8139too.c, drivers/scsi/aic7xxx/aic7xxx_osm_pci.c, whatever.
static int __devinit mantis_pci_probe(struct pci_dev *pdev, const struct
pci_device_id *mantis_pci_table)
{
u8 revision, latency;
u8 data[2];
struct mantis_pci *mantis;
mantis = (struct mantis_pci *) kmalloc(sizeof (struct mantis_pci),
GFP_KERNEL);
if (mantis == NULL) {
dprintk(verbose, MANTIS_ERROR, 1, "Out of memory");
return -ENOMEM;
}
pdev = pci_get_device(PCI_VENDOR_ID_MANTIS, PCI_DEVICE_ID_MANTIS_R11,
NULL);
This is not needed anymore then. Your probe function will get called with for any pci dev your driver can handle.
if (pdev) {
dprintk(verbose, MANTIS_ERROR, 1, "Got a device");
mantis->mantis_addr = pci_resource_start(pdev, 0);
if (!request_mem_region(pci_resource_start(pdev, 0),
pci_resource_len(pdev, 0), DRIVER_NAME)) {
dprintk(verbose, MANTIS_ERROR, 1, "Request for memory region failed");
Line length is maximum 80 characters. See Documentation/CodingStyle
Ah, thanks ...
goto err0;
}
if ((mantis->mantis_mmio = ioremap(mantis->mantis_addr, 0x1000)) == NULL) {
dprintk(verbose, MANTIS_ERROR, 1, "IO remap failed");
goto err1;
}
if (request_irq(pdev->irq, (void *) mantis_pci_irq, SA_SHIRQ |
SA_INTERRUPT, DRIVER_NAME, (void *) mantis) < 0) {
You don't need to cast a pointer to void* or vice versa.
dprintk(verbose, MANTIS_ERROR, 1, "Mantis IRQ registration failed");
goto err2;
}
dprintk(verbose, MANTIS_DEBUG, 1, "We got an IRQ");
if (pci_enable_device(pdev)) {
dprintk(verbose, MANTIS_ERROR, 1, "Mantis PCI device enable failed");
goto err3;
}
dprintk(verbose, MANTIS_DEBUG, 1, "We finally enabled the device");
pci_set_master(pdev);
pci_read_config_byte(pdev, PCI_LATENCY_TIMER, &latency);
pci_read_config_byte(pdev, PCI_CLASS_REVISION, &revision);
mantis->latency = latency;
mantis->revision = revision;
if (!latency) {
pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 32);
}
The value in mantis->latency and the one in the card's address space now differ.
pci_set_drvdata(pdev, mantis);
dprintk(verbose, MANTIS_ERROR, 0, "Mantis Rev %d, ", mantis->revision);
dprintk(verbose, MANTIS_ERROR, 0, "irq: %d, latency: %d\nmemory:
0x%04x, mmio: %p\n", pdev->irq, mantis->latency,
mantis->mantis_addr, mantis->mantis_mmio);
pci_dev_put(pdev);
No, DON'T DO THAT! This will drop the a reference count from the struct pci_dev, which means it can get freed while your driver still wants to work with it.
Ack.} else {
dprintk(verbose, MANTIS_ERROR, 1, "No device found");
return -ENODEV;
}
err3:
free_irq(pdev->irq, pdev);
err2:
if (mantis->mantis_mmio)
iounmap(mantis->mantis_mmio);
err1:
release_mem_region(pci_resource_start(pdev, 0),
pci_resource_len(pdev, 0));
err0:
kfree(mantis);
return 0;
}
static void __devexit mantis_pci_remove(struct pci_dev *pdev)
{
struct mantis_pci *mantis = pci_get_drvdata(pdev);
if (mantis == NULL) {
dprintk(verbose, MANTIS_ERROR, 1, "Aeio, MAntis NULL ptr");
a) this should really never happen. If it happens, it's a kernel bug.
b) if you catch this error while debugging, you should return here so you do
not dereference this NULL pointer.
}
dprintk(verbose, MANTIS_ERROR, 1, "Removing -->Mantis irq: %d, latency:
%d\nmemory: 0x%04x, mmio: 0x%p", pdev->irq, mantis->latency,
mantis->mantis_addr, mantis->mantis_mmio);
free_irq(pdev->irq, pdev);
release_mem_region(pci_resource_start(pdev, 0),
pci_resource_len(pdev, 0));
pci_disable_device(pdev);
pci_set_drvdata(pdev, NULL);
kfree(mantis);
}