Re: [PATCH 5/8] firmware/sysfb: Create firmware device only for enabled PCI devices

Thomas Zimmermann [off-list ref] writes:

Test if the firmware framebuffer's parent PCI device, if any, has
been enabled. If not, the firmware framebuffer is most likely not
working. Hence, do not create a device for the firmware framebuffer
on disabled PCI devices.

So far, efifb tracked the status of the PCI parent device internally
and did not bind if it was disabled. This patch implements the
functionality for all firmware framebuffers.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---

[...]

 
+static __init bool sysfb_pci_dev_is_enabled(struct pci_dev *pdev)
+{
+#if defined(CONFIG_PCI)
+	/*
+	 * TODO: Try to integrate this code into the PCI subsystem
+	 */
+	int ret;
+	u16 command;
+
+	ret = pci_read_config_word(pdev, PCI_COMMAND, &command);
+	if (ret != PCIBIOS_SUCCESSFUL)
+		return false;
+	if (!(command & PCI_COMMAND_MEMORY))
+		return false;
+	return true;
+#else
+	// Getting here without PCI support is probably a bug.
+	return false;

Should we warn before return in this case ?

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat