3rd-party/linux-kernel-module-cheat
1
0
Fork 0
mirror of https://github.com/cirosantilli/linux-kernel-module-cheat.git synced 2026-01-23 10:15:57 +01:00
Code Issues Releases Wiki Activity

pci works even after device_add

Browse Source
This commit is contained in:
Ciro Santilli
2017-06-27 22:12:31 +01:00
parent 9b11287795
commit 7ae74bfcce
1 changed files with 13 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
kernel_module/pci.c
View File

@@ -73,7 +73,7 @@ TODO: does it have any side effects? Set in the edu device at:
*
* - IORESOURCE_IO: must be accessed with inX and outX
* - IORESOURCE_MEM: must be accessed with ioreadX and iowriteX
* This is the saner method apparently, and what the edu device uses.
* This is the saner method apparently, and what the edu device uses.
*
* The length of each region is defined BY THE HARDWARE, and communicated to software
* via the configuration registers.
@@ -101,7 +101,6 @@ static struct pci_device_id pci_ids[] = {
};
MODULE_DEVICE_TABLE(pci, pci_ids);
static int pci_irq;
static int major;
static struct pci_dev *pdev;
static void __iomem *mmio;
@@ -189,8 +188,6 @@ static irqreturn_t irq_handler(int irq, void *dev)
*/
static int pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
u8 val;
/* https://stackoverflow.com/questions/31382803/how-does-dev-family-functions-are-useful-while-debugging-kernel/44734857#44734857 */
dev_info(&(dev->dev), "pci_probe\n");
major = register_chrdev(0, CDEV_NAME, &fops);
@@ -205,10 +202,15 @@ static int pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
}
mmio = pci_iomap(pdev, BAR, pci_resource_len(pdev, BAR));
/* IRQ setup. */
pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &val);
pci_irq = val;
if (request_irq(pci_irq, irq_handler, IRQF_SHARED, "pci_irq_handler0", &major) < 0) {
/* IRQ setup.
*
* pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &val);
* has a different value and does not work if we insert the PCI device
* after boot with device_add:
* https://stackoverflow.com/questions/44740254/how-to-handle-interrupts-from-a-pci-device-that-already-have-a-non-shareable-han?noredirect=1#comment76558680_44740254
*/
pr_info("pdev->irq %u\n", pdev->irq);
if (request_irq(pdev->irq, irq_handler, IRQF_SHARED, "pci_irq_handler0", &major) < 0) {
dev_err(&(dev->dev), "request_irq\n");
goto error;
}
@@ -216,6 +218,7 @@ static int pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
/* Optional sanity checks. The PCI is ready now, all of this could also be called from fops. */
{
unsigned i;
u8 val;
/* Check that we are using MEM instead of IO.
*
@@ -239,7 +242,7 @@ static int pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
pci_read_config_byte(pdev, i, &val);
pr_info("config %x %x\n", i, val);
}
pr_info("irq %x\n", pci_irq);
pr_info("irq %x\n", pdev->irq);
/* Initial value of the IO memory. */
for (i = 0; i < 0x28; i += 4) {
@@ -254,7 +257,7 @@ error:
static void pci_remove(struct pci_dev *dev)
{
pr_info("pci_remove\n");
free_irq(pci_irq, &major);
free_irq(pdev->irq, &major);
pci_release_region(dev, BAR);
unregister_chrdev(major, CDEV_NAME);
}