On Sat, Aug 11, 2018 at 12:35:39PM -0700, Andrey Smirnov wrote: > 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. Applied now, thanks Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
