Hi,


On 2024/2/2 19:58, Thomas Zimmermann wrote:

+
+/**
+ * screen_info_pci_dev() - Return PCI parent device that contains screen_info's framebuffer
+ * @si: the screen_info
+ *
+ * Returns:
+ * The screen_info's parent device on success, or NULL otherwise.
+ */
+struct pci_dev *screen_info_pci_dev(const struct screen_info *si)
+{
+	struct resource res[SCREEN_INFO_MAX_RESOURCES];
+	ssize_t i, numres;
+
+	numres = screen_info_resources(si, res, ARRAY_SIZE(res));
+	if (numres < 0)
+		return ERR_PTR(numres);

Please return NULL at here, otherwise we have to use the IS_ERR or IS_ERR_OR_NULL()
in the caller function to check the returned value. Meanwhile, I noticed that you
didn't actually call IS_ERR() in the sysfb_parent_dev() function (introduced by the
3/8 patch), so I think we probably should return NULL at here.

Please also consider that the comments of this function says that it return NULL on
the otherwise cases.

+	for (i = 0; i < numres; ++i) {
+		struct pci_dev *pdev = __screen_info_pci_dev(&res[i]);
+
+		if (pdev)
+			return pdev;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(screen_info_pci_dev);