[PATCH 3.16 122/148] platform/x86: hp-wmi: Fix ACPI errors caused by passing 0 as input size

[Ben Hutchings]

3.16.82-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Hans de Goede <hdegoede@xxxxxxxxxx>

commit f3e4f3fc8ee9729c4b1b27a478c68b713df53c0c upstream.

The AML code implementing the WMI methods creates a variable length
field to hold the input data we pass like this:

        CreateDWordField (Arg1, 0x0C, DSZI)
        Local5 = DSZI /* \HWMC.DSZI */
        CreateField (Arg1, 0x80, (Local5 * 0x08), DAIN)

If we pass 0 as bios_args.datasize argument then (Local5 * 0x08)
is 0 which results in these errors:

[   71.973305] ACPI BIOS Error (bug): Attempt to CreateField of length zero (20190816/dsopcode-133)
[   71.973332] ACPI Error: Aborting method \HWMC due to previous error (AE_AML_OPERAND_VALUE) (20190816/psparse-529)
[   71.973413] ACPI Error: Aborting method \_SB.WMID.WMAA due to previous error (AE_AML_OPERAND_VALUE) (20190816/psparse-529)

And in our HPWMI_WIRELESS2_QUERY calls always failing. for read commands
like HPWMI_WIRELESS2_QUERY the DSZI value is not used / checked, except for
read commands where extra input is needed to specify exactly what to read.

So for HPWMI_WIRELESS2_QUERY we can safely pass the size of the expected
output as insize to hp_wmi_perform_query(), as we are already doing for all
other HPWMI_READ commands we send. Doing so fixes these errors.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=197007
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=201981
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1520703
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/platform/x86/hp-wmi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/platform/x86/hp-wmi.c
+++ b/drivers/platform/x86/hp-wmi.c
@@ -400,7 +400,7 @@ static int hp_wmi_rfkill2_refresh(void)
 	struct bios_rfkill2_state state;
 
 	err = hp_wmi_perform_query(HPWMI_WIRELESS2_QUERY, 0, &state,
-				   0, sizeof(state));
+				   sizeof(state), sizeof(state));
 	if (err)
 		return err;
 
@@ -825,7 +825,7 @@ static int __init hp_wmi_rfkill2_setup(s
 	int err, i;
 	struct bios_rfkill2_state state;
 	err = hp_wmi_perform_query(HPWMI_WIRELESS2_QUERY, 0, &state,
-				   0, sizeof(state));
+				   sizeof(state), sizeof(state));
 	if (err)
 		return err;