On Mon, May 14, 2018 at 11:07 PM Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > > On Mon, May 14, 2018 at 05:20:56PM -0700, Andrey Smirnov wrote: > > On Mon, May 14, 2018 at 12:14 AM, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > > > On Tue, May 08, 2018 at 02:15:02PM -0700, Andrey Smirnov wrote: > > >> With serdev device support added there's now a corner case where: > > >> > > >> 1. There is a DT node for a serdev device on one of the UARTs > > >> 2. There is no driver that binds against serdev device's compatibility > > >> string > > >> > > >> with 1 and 2 being true it is possible to end up in a situation where > > >> a particualr UART has not been initalized to any baudrate when > > >> clock_notifier_call_chain() gets called. This effectively translates > > >> to > > >> > > >> set_baudrate(uart, 0); > > >> > > >> which for LPUART driver result in a division by zero. > > > > > > This probably leads to a division by zero for most drivers since > > > dividing by the baudrate is a common pattern. Wouldn't it be better to > > > catch this is console_set_baudrate()? > > > > > > > It would, but none of the drivers that register a callback with > > clock_register_client() (serial_imx.c, serial_auart.c, stm-serial.c, > > serial_lpuart.c and serial_cadence.c) use console_set_badrate() and > > instead call ->setbrg() directly. Probably because > > console_set_baudrate() also handles interactive baudrate switch for > > f_active console devices. Serial_imx.c doesn't preform any division, > > so it is safe and I can go through the rest of them to add appropriate > > checks? Another option is probably to try to come up with common > > clock_register_client() infrastructure(since all of the handlers are > > the same) and keep that check there. > > > > Let me know if you want me to do either. > > I see. For the sake of simplicity I think we can go with your original > patch. In the auart and cadence driver the clock notify stuff is unused, > only copy paste leftover from copying the i.MX driver. That leaves the > lpuart driver which really has this problem. > Sascha, I don't think this patch ever made it into master. I am assuming it just slipped through the cracks. Let me know if anything needs changing for it to be applied. Thanks, Andrey Smirnov _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
