On Thu, Oct 1, 2020 at 9:42 PM Avi Fishman <avifishman70@xxxxxxxxx> wrote: > > Tali indeed pointed our major customers (Alex represent one of them :) > that this feature must be handled carefully since it may break the > communication and they are aware of that. Nevertheless they still want > this feature, they already reviewed this and accepted it (in internal > mails) > > So we will appreciate if this will be accepted. > > On Thu, Oct 1, 2020 at 9:27 PM Alex Qiu <xqiu@xxxxxxxxxx> wrote: > > > > On Thu, Oct 1, 2020 at 10:41 AM Andy Shevchenko > > <andy.shevchenko@xxxxxxxxx> wrote: > > > > > > On Thu, Oct 01, 2020 at 08:13:49PM +0300, Avi Fishman wrote: > > > > Hi Andy, > > > > > > > > Customers using BMC with complex i2c topology asked us to support > > > > changing bus frequency at run time, for example same device will > > > > communicate with one slave at 100Kbp/s and another with 400kbp/s and > > > > maybe also with smae device at different speed (for example an i2c > > > > mux). > > > > This is not only for debug. > > > > > > The above design is fragile to start with. If you have connected peripheral > > > devices with different speed limitations and you try to access faster one the > > > slower ones may block and break the bus which will need recovery. > > > > > > > Hi Andy, > > > > To clarify, we are using a single read-only image to support multiple > > configurations, so the supported bus rate of the devices are not known > > at compile time, but at runtime. We start with 100 kHz, and go 400 kHz > > if applicable. FYI, we are using 5.1 kernel, however I don't know much > > about DT overlay. I see. So, there are following statements: - the elaboration is good but I guess needs to be added somewhere in form of the documentation - the internal schedules or so are not crucial for the upstream (it rather sounds like a bribing the judge) - the current approach, if I'm not mistaken, is using debugfs, which is not ABI and it's good - I'm not a maintainer here, but I don't like the approach Let the maintainer decide. -- With Best Regards, Andy Shevchenko
