[patch 56/58] ACPI: EC: Add some basic check for ECDT data

From: Greg KH
Date: Wed Apr 29 2009 - 18:44:38 EST


2.6.27-stable review patch. If anyone has any objections, please let us know.

------------------

From: Alexey Starikovskiy <astarikovskiy@xxxxxxx>

commit c5279dee26c0e8d7c4200993bfc4b540d2469598 upstream.

One more ASUS comes with empty ECDT, add a guard for it...

http://bugzilla.kernel.org/show_bug.cgi?id=11880

Signed-off-by: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/acpi/ec.c | 43 ++++++++++++++++++++++---------------------
1 file changed, 22 insertions(+), 21 deletions(-)

--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -968,7 +968,6 @@ static const struct acpi_device_id ec_de

int __init acpi_ec_ecdt_probe(void)
{
- int ret;
acpi_status status;
struct acpi_table_ecdt *ecdt_ptr;

@@ -996,30 +995,32 @@ int __init acpi_ec_ecdt_probe(void)
boot_ec->gpe = ecdt_ptr->gpe;
boot_ec->handle = ACPI_ROOT_OBJECT;
acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
- } else {
- /* This workaround is needed only on some broken machines,
- * which require early EC, but fail to provide ECDT */
- acpi_handle x;
- printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
- status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
- boot_ec, NULL);
- /* Check that acpi_get_devices actually find something */
- if (ACPI_FAILURE(status) || !boot_ec->handle)
- goto error;
- /* We really need to limit this workaround, the only ASUS,
- * which needs it, has fake EC._INI method, so use it as flag.
- * Keep boot_ec struct as it will be needed soon.
- */
- if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
- return -ENODEV;
+ /* Add some basic check against completely broken table */
+ if (boot_ec->data_addr != boot_ec->command_addr)
+ goto install;
+ /* fall through */
}
-
- ret = ec_install_handlers(boot_ec);
- if (!ret) {
+ /* This workaround is needed only on some broken machines,
+ * which require early EC, but fail to provide ECDT */
+ acpi_handle x;
+ printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
+ status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
+ boot_ec, NULL);
+ /* Check that acpi_get_devices actually find something */
+ if (ACPI_FAILURE(status) || !boot_ec->handle)
+ goto error;
+ /* We really need to limit this workaround, the only ASUS,
+ * which needs it, has fake EC._INI method, so use it as flag.
+ * Keep boot_ec struct as it will be needed soon.
+ */
+ if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
+ return -ENODEV;
+install:
+ if (!ec_install_handlers(boot_ec)) {
first_ec = boot_ec;
return 0;
}
- error:
+error:
kfree(boot_ec);
boot_ec = NULL;
return -ENODEV;


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