Re: [PATCH] wan: lmc: Switch to using managed resources

On Wed, Mar 2, 2016 at 3:51 AM, David Miller [off-list ref] wrote:

From: Amitoj Kaur Chawla <redacted>
Date: Sat, 27 Feb 2016 22:34:16 +0530

quoted

@@ -835,23 +835,20 @@ static int lmc_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
      err = pci_request_regions(pdev, "lmc");
      if (err) {
              printk(KERN_ERR "lmc: pci_request_region failed\n");
-             goto err_req_io;
+             return err;
      }

      /*
       * Allocate our own device structure
       */
-     sc = kzalloc(sizeof(lmc_softc_t), GFP_KERNEL);
-     if (!sc) {
-             err = -ENOMEM;
-             goto err_kzalloc;

You can't get rid of the error paths from here on out, because you still need to
release the PCI regions obtained from pci_request_regions() above.

To be quite honest, unless you are fixing real bugs, managed resource
converstions are more likely to add bugs than do anything truly
useful.

I strongly consider you just drop this change.

Hi David,

I checked pcim_enable_device() before sending the patch, it has a call
to pcim_release() which does disabling of the PCI device and the
releasing of PCI regions obtained from pci_request_regions so there is
no need for pci_release_regions or pci_disable_device anymore.

Specifically, pcim_release contains the following code:

for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)
  if (this->region_mask & (1 << i))
    pci_release_region(dev, i);

Also, commit id add243d5bc371eef66f81c9da4fd4b55a18dad23 is a similar
change that further made me believe that the change is a correct one.

However, if you think I am wrong somewhere and I understood things
incorrectly, please correct me.

Thanks,
Amitoj