On Monday, December 22, 2014 12:19:44 PM Jakub Sitnicki wrote: > On Fri, Dec 12, 2014 at 08:47 AM CET, Jakub Sitnicki wrote: > > Rafael J. Wysocki <[email protected]> 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; > > } > > Just wondering, do you have any further thoughts on this?
I'll queue it up for 3.20 later in January. -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
