[PATCH v2] media: saa7164: fix cleanup on resource allocation failure

[Guangshuo Li]

saa7164_dev_setup() adds the device to the global saa7164_devlist before
requesting the PCI BAR memory regions.

If get_resources() fails, saa7164_dev_setup() decrements the device count
and returns an error, but leaves the device on saa7164_devlist. The probe
error path then frees the device, leaving a dangling entry on the global
list.

Reuse the existing MMIO mapping error path to remove the device from
saa7164_devlist and decrement the device count before returning.

Also release BAR0 if it was successfully requested but the BAR2 request
fails.

Fixes: 443c1228d505 ("V4L/DVB (12923): SAA7164: Add support for the NXP SAA7164 silicon")
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
v2:
  - Reuse the existing error handling path instead of duplicating the device
    list cleanup, as suggested by Hans Verkuil.
  - Add a new error label after release_resources() for failures where no PCI
    resources need to be released.

 drivers/media/pci/saa7164/saa7164-core.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/media/pci/saa7164/saa7164-core.c b/drivers/media/pci/saa7164/saa7164-core.c
index 6bcde506adf5..db65506ea885 100644
--- a/drivers/media/pci/saa7164/saa7164-core.c
+++ b/drivers/media/pci/saa7164/saa7164-core.c
@@ -878,6 +878,9 @@ static int get_resources(struct saa7164_dev *dev)
 		if (request_mem_region(pci_resource_start(dev->pci, 2),
 			pci_resource_len(dev->pci, 2), dev->name))
 			return 0;
+
+		release_mem_region(pci_resource_start(dev->pci, 0),
+				   pci_resource_len(dev->pci, 0));
 	}
 
 	printk(KERN_ERR "%s: can't get MMIO memory @ 0x%llx or 0x%llx\n",
@@ -1000,8 +1003,7 @@ static int saa7164_dev_setup(struct saa7164_dev *dev)
 		       dev->name, dev->pci->subsystem_vendor,
 		       dev->pci->subsystem_device);
 
-		saa7164_devcount--;
-		return -ENODEV;
+		goto err_devlist;
 	}
 
 	/* PCI/e allocations */
@@ -1039,7 +1041,7 @@ static int saa7164_dev_setup(struct saa7164_dev *dev)
 	iounmap(dev->lmmio);
 err_ioremap_bar0:
 	release_resources(dev);
-
+err_devlist:
 	scoped_guard(mutex, &devlist) {
 		list_del(&dev->devlist);
 	}
-- 
2.43.0