Messages in this thread | | | Date | Mon, 01 Mar 2004 20:48:59 +0800 | From | "Michael Frank" <> | Subject | Re: [Swsusp-devel] Re: Dropping CONFIG_PM_DISK? |
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On Mon, 01 Mar 2004 22:39:52 +1100, Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> >> >> - that 2.4 style PM got depreciated and let die before the >> >> "new-driver-model" PM is workin >> > >> > Except that it never worked >> >> It is actively used for ide, network, serial drivers with swsusp2. > > Without any proper ordering guarantee, IDE could take requests > after beeing suspended, which could be fatal (and cause data loss) > etc...
Appreciated, suspending a driver like sending XOFF to a tty is ideal, but not neccessary for _most_ drivers (software suspend) purpose.
Wrt IDE, in practice all processes get frozen well before suspending drivers. Tested and no issues were ever reported with 2.4.
> > Moving to the new model is easy. I don't see why we should have had > such a "compatibility" path on a major kernel version, that makes > no sense, just help fixing the drivers that need more fixing instead.
What for write new drivers for (fast obsoleting) hardware?.
- Developer time is the most precious resource - Testing of drivers is in practice very difficult due to lack of several variations of HW (one can't really test anything in one box) - It will take _years_ for drivers to become available and reach the stability of 2.4 drivers. - Many drivers will die for lack of overall resources to port them.
So, why burn resources on reinventing wheels, which end up poorly tested and run like a disk sliced of a tree...
What is needed is a _compatible_ infrastructure to _any_ 2.4 driver in existence and also provideing rudimentary centralized suspend and resume capability.
This infrastructure could even be a config option CONFIG_24_DRIVER_SUPPORT and be independent of the new model.
Then one could just drop in a driver from 2.4 and use it.
People having time to make new "pretty" drivers could also use this facility for cross checking.
> >> > >> >> - that perfectly good drivers were rewritten from scratch, >> >> but without functioning PM support >> > >> > Please, give names. >> > >> >> A few I tested: >> >> AGP (sis, savage) >> trident (Ali153x) >> Serial (82x50) >> Yenta (Toshiba Topic95) >> >> Regards >> Michael
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