Unlike it's Linux counterpart, clk_get_rate can return a negative value, -ve. The driver does not take that into account, stores the rate into an unsigned long, and if clk_get_rate fails, it will take into consideration the actual value and wrongly program the hardware. E.g. on error -2 (no such entry), the rate will be 18446744073709551614 and this will be subsequently used by the driver to program the DWC3 To fix this, exit the function if the value is negative.
Fixes: 6bae0eb5b8bd ("usb: dwc3: Calculate REFCLKPER based on reference clock") Signed-off-by: Eugen Hristev eugen.hristev@collabora.com --- drivers/usb/dwc3/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 49f6a1900b01..5a8c29424578 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -138,7 +138,7 @@ static void dwc3_ref_clk_period(struct dwc3 *dwc)
if (dwc->ref_clk) { rate = clk_get_rate(dwc->ref_clk); - if (!rate) + if (!rate || (long)rate < 0) return; period = NSEC_PER_SEC / rate; } else {