Hello ksi, k...@koi8.net wrote: > On Wed, 18 Feb 2009, Heiko Schocher wrote: > >> Hello Wolfgang, >> >> Wolfgang Denk wrote: >>> Dear k...@koi8.net, >>> >>> In message <pine.lnx.4.64ksi.0902171233390.30...@home-gw.koi8.net> you >>> wrote: >> [...] >>>>> What makes you insist that we cannot change a variable if we need to >>>>> be able to change one? >>>> It is NOT just variable. My approach uses i2c _BUS_, not _ADAPTER_. And >>>> number of busses can be bigger than number of adapters (e.g. when some >>>> busses a reached via muxes or switches.) When doing i2c_set_current_bus() >>>> you are switching _NOT_ adapters, but busses. That involves not only >>>> changing that global variable but also reprogramming muxes/switches for >>>> i2c_set_current_bus() to be consistent and hardware independent. Otherwise >>>> your code should know if that particular bus it is switching to is directly >>>> connected or switched and check the bus it is switching from for muxes. If >>>> they are switched, your code should disconnect the current bus switches, >>>> then do that i2c_set_current_bus() and connect the switches to the new bus >>>> after that. >>>> >>>> That means that code MUST somehow know the topology to take appropriate >>>> actions and properly configure those switches. That means you should >>>> somehow >>>> describe that topology for each and every board in CONFIG_* terms and make >>>> each and every place at U-Boot that invokes _ANY_ i2c function to take care >>>> of that switching. >>> You convinced me. This code must not be used before relocation to RAM, >>> then. >> But is is possible to use that code when running from flash, if >> this current pointer is writeable ... > > It is not the pointer that must be writeable, it's what it is pointing to...
But in your approach this is also not writeable! So we lost nothing, when using such a pointer. bye Heiko -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
