Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> writes: > On Monday, December 08, 2014 10:01:57 PM Jakub Sitnicki wrote: >> diff --git a/drivers/pnp/resource.c b/drivers/pnp/resource.c >> index 782e822..f980ff7 100644 >> --- a/drivers/pnp/resource.c >> +++ b/drivers/pnp/resource.c >> @@ -179,8 +179,9 @@ int pnp_check_port(struct pnp_dev *dev, struct resource *res) >> /* check if the resource is already in use, skip if the >> * device is active because it itself may be in use */ >> if (!dev->active) { >> - if (__check_region(&ioport_resource, *port, length(port, end))) >> + if (!request_region(*port, length(port, end), "pnp")) >> return 0; >> + release_region(*port, length(port, end)); > > Shouldn't we also release the resource returned by request_region() if it is > not NULL? > Thanks for taking a look at this. I think we're good here. If you please bear with me for a moment: release_resource() removes an element from the list of resource parent's children (and makes it an orphan): p = &old->parent->child; for (;;) { tmp = *p; if (!tmp) break; if (tmp == old) { *p = tmp->sibling; old->parent = NULL; return 0; } p = &tmp->sibling; } release_region() does the same but with additional checks, and also frees the resource: p = &parent->child; /* ... */ for (;;) { struct resource *res = *p; if (!res) break; if (res->start <= start && res->end >= end) { /* ... */ *p = res->sibling; /* ... */ free_resource(res); return; } p = &res->sibling; } When making the change I've based on other code in the kernel which also make use of request_region(). To quote one example, drivers/net/ethernet/8390/ne2k-pci.c cleans up its I/O port region when initialization fails like so: static int ne2k_pci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) { /* ... */ if (request_region (ioaddr, NE_IO_EXTENT, DRV_NAME) == NULL) { dev_err(&pdev->dev, "I/O resource 0x%x @ 0x%lx busy\n", NE_IO_EXTENT, ioaddr); return -EBUSY; } /* ... */ dev = alloc_ei_netdev(); if (!dev) { dev_err(&pdev->dev, "cannot allocate ethernet device\n"); goto err_out_free_res; } /* ... */ err_out_free_res: release_region (ioaddr, NE_IO_EXTENT); return -ENODEV; } >> } >> >> /* check if the resource is reserved */ >> @@ -241,8 +242,9 @@ int pnp_check_mem(struct pnp_dev *dev, struct resource *res) >> /* check if the resource is already in use, skip if the >> * device is active because it itself may be in use */ >> if (!dev->active) { >> - if (check_mem_region(*addr, length(addr, end))) >> + if (!request_mem_region(*addr, length(addr, end), "pnp")) >> return 0; >> + release_mem_region(*addr, length(addr, end)); >> } >> >> /* check if the resource is reserved */ >> -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html