The value returned by acpi_evaluate_integer() is not checked, but the result is not always successful, so it is necessary to add a check of the returned value.
If the result remains negative during three iterations of the loop, then the uninitialized variable 'val' will be used in the clamp_val() macro, so it must be initialized with the current value of the 'curr' variable.
In this case, the algorithm should be less noisy.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: b23910c2194e ("asus-laptop: Pegatron Lucid accelerometer") Cc: stable@vger.kernel.org Signed-off-by: Denis Arefev arefev@swemel.ru --- V1 -> V2: Added check of the return value it as Ilpo Järvinen ilpo.jarvinen@linux.intel.com suggested. Changed initialization of 'val' variable it as Ilpo Järvinen ilpo.jarvinen@linux.intel.com suggested.
drivers/platform/x86/asus-laptop.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/platform/x86/asus-laptop.c b/drivers/platform/x86/asus-laptop.c index d460dd194f19..ff674c6d0bbb 100644 --- a/drivers/platform/x86/asus-laptop.c +++ b/drivers/platform/x86/asus-laptop.c @@ -427,10 +427,12 @@ static int asus_pega_lucid_set(struct asus_laptop *asus, int unit, bool enable) static int pega_acc_axis(struct asus_laptop *asus, int curr, char *method) { int i, delta; - unsigned long long val; + acpi_status status; + unsigned long long val = (unsigned long long)curr; for (i = 0; i < PEGA_ACC_RETRIES; i++) { - acpi_evaluate_integer(asus->handle, method, NULL, &val); - + status = acpi_evaluate_integer(asus->handle, method, NULL, &val); + if (ACPI_FAILURE(status)) + continue; /* The output is noisy. From reading the ASL * dissassembly, timeout errors are returned with 1's * in the high word, and the lack of locking around