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Add Lenovo IdeaPad Y470/Y570 hack

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Warning: this is a very ugly hack, I do not know whether it works or not. It may
be unstable and does very unusual things.
This commit is contained in:
Lekensteyn
2012-02-02 22:23:13 +01:00
parent 7c30e38bd1
commit 3668be9736
1 changed files with 85 additions and 0 deletions
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85
acpi-handle-hack.c Normal file
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/**
* Very ugly hack to work around a wrongly detected ACPI handle, see
* https://bugzilla.kernel.org/show_bug.cgi?id=42696
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/dmi.h>
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Dirty ACPI handle hack for Lenovo IdeaPad Y[45]70");
MODULE_AUTHOR("Peter Lekensteyn <lekensteyn@gmail.com>");
MODULE_VERSION("0.0.1");
static struct pci_dev *dis_dev;
static acpi_handle orig_handle;
/**
* Returns true if the system needs an ACPI handle hack
*/
static bool __init need_acpi_handle_hack(void) {
return dmi_match(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y470") ||
dmi_match(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y570");
}
static struct pci_dev __init *get_discrete_device(void) {
struct pci_dev *pdev = NULL;
int class = PCI_CLASS_DISPLAY_VGA << 8;
while ((pdev = pci_get_class(class, pdev)) != NULL) {
if (pdev->vendor != PCI_VENDOR_ID_INTEL) {
return pdev;
}
}
return NULL;
}
/**
* Very ugly hack to set the ACPI handle, do not use this as exemplary code!
*/
static void dev_set_acpi_handle(struct pci_dev *pdev, acpi_handle handle) {
pdev->dev.archdata.acpi_handle = handle;
}
static int __init hack_apply(void) {
acpi_handle tmp_handle, new_handle;
struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
if (!need_acpi_handle_hack()) {
printk(KERN_ERR "Machine does not need ACPI handle hack\n");
return -ENODEV;
}
dis_dev = get_discrete_device();
if (!dis_dev) {
printk(KERN_ERR "No discrete video card found\n");
return -ENODEV;
}
orig_handle = DEVICE_ACPI_HANDLE(&dis_dev->dev);
if (!orig_handle) {
printk(KERN_ERR "No ACPI handle found for discrete\n");
return -ENODEV;
}
acpi_get_name(orig_handle, ACPI_SINGLE_NAME, &buf);
if (strcmp((char *)buf.pointer, "PEGP") == 0) {
printk(KERN_ERR "Handle has already be changed\n");
return -ENODEV;
}
/* \_SB.PCI0.PEG0.VGA_ -> \_SB.PCI0.PEG0.PEGP */
acpi_get_parent(orig_handle, &tmp_handle);
acpi_get_handle(tmp_handle, "PEGP", &new_handle);
printk(KERN_INFO "Setting new ACPI handle for discrete video card\n");
dev_set_acpi_handle(dis_dev, new_handle);
pci_dev_put(dis_dev);
return 0;
}
static void __exit hack_undo(void) {
if (orig_handle) {
printk(KERN_INFO "Restoring original ACPI handle for discrete"
" video card\n");
dev_set_acpi_handle(dis_dev, orig_handle);
}
}
module_init(hack_apply);
module_exit(hack_undo);