[PATCH] mISDN: Fix return values of the probe function

During the process of driver probing, the probe function should return < 0
for failure, otherwise, the kernel will treat value > 0 as success.

Signed-off-by: Zheyu Ma <redacted>
---
 drivers/isdn/hardware/mISDN/hfcpci.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c
index e501cb03f211..bd087cca1c1d 100644
--- a/drivers/isdn/hardware/mISDN/hfcpci.c
+++ b/drivers/isdn/hardware/mISDN/hfcpci.c

@@ -1994,14 +1994,14 @@ setup_hw(struct hfc_pci *hc)
 	pci_set_master(hc->pdev);
 	if (!hc->irq) {
 		printk(KERN_WARNING "HFC-PCI: No IRQ for PCI card found\n");
-		return 1;
+		return -EINVAL;
 	}
 	hc->hw.pci_io =
 		(char __iomem *)(unsigned long)hc->pdev->resource[1].start;
 
 	if (!hc->hw.pci_io) {
 		printk(KERN_WARNING "HFC-PCI: No IO-Mem for PCI card found\n");
-		return 1;
+		return -ENOMEM;
 	}
 	/* Allocate memory for FIFOS */
 	/* the memory needs to be on a 32k boundary within the first 4G */

@@ -2012,7 +2012,7 @@ setup_hw(struct hfc_pci *hc)
 	if (!buffer) {
 		printk(KERN_WARNING
 		       "HFC-PCI: Error allocating memory for FIFO!\n");
-		return 1;
+		return -ENOMEM;
 	}
 	hc->hw.fifos = buffer;
 	pci_write_config_dword(hc->pdev, 0x80, hc->hw.dmahandle);

@@ -2022,7 +2022,7 @@ setup_hw(struct hfc_pci *hc)
 		       "HFC-PCI: Error in ioremap for PCI!\n");
 		dma_free_coherent(&hc->pdev->dev, 0x8000, hc->hw.fifos,
 				  hc->hw.dmahandle);
-		return 1;
+		return -ENOMEM;
 	}
 
 	printk(KERN_INFO

-- 
2.17.6

10/18/21 5:20 PM, Zheyu Ma пишет:

During the process of driver probing, the probe function should return < 0
for failure, otherwise, the kernel will treat value > 0 as success.

setup_card() checks for the return value.
Thus it makes sense to submit the patch with net-next tag

On Mon, 18 Oct 2021 20:06:51 +0300 Denis Kirjanov wrote:

10/18/21 5:20 PM, Zheyu Ma пишет:

quoted

During the process of driver probing, the probe function should return < 0
for failure, otherwise, the kernel will treat value > 0 as success.  

setup_card() checks for the return value.
Thus it makes sense to submit the patch with net-next tag

setup_card() propagates the value returned by setup_hw() which in turn
gets propagated by hfc_probe() and hits local_pci_probe():

	/*
	 * Probe function should return < 0 for failure, 0 for success
	 * Treat values > 0 as success, but warn.
	 */
	pci_warn(pci_dev, "Driver probe function unexpectedly returned %d\n",
		 rc);
	return 0;

But you're right, this is a minor bug, hfc_remove_pci() checks if
driver data is already NULL so there will be no crash. Just a driver
bound to a device even though probe failed. Still net material tho.