From: Sergei Shtylyov <sshtylyov@ru•mvista.com>
To: Segher Boessenkool <segher@kernel•crashing.org>
Cc: ppcdev <linuxppc-dev@ozlabs•org>,
linux-mtd@lists•infradead.org, Milton Miller <miltonm@bga•com>
Subject: Re: [PATCH] powerpc: Create "rom" (MTD) device prpmc2800
Date: Sun, 03 Jun 2007 22:18:52 +0400 [thread overview]
Message-ID: <4663060C.2020906@ru.mvista.com> (raw)
In-Reply-To: <a5dde31321a50ed198cf4fc199e4af9c@kernel.crashing.org>
Segher Boessenkool wrote:
>>> I think "direct-mapped" as compatible is a bit too broad or vague.
>> It's actually not -- it means simple 1:1 address mapping (w/o
>> explicit
>> byte-swapping and such).
> Which has nothing to do with "compatible"; instead,
> it is implied by the parent node have a "ranges"
No! It doesn't have anything to do with "ranges" of parent (don't even
know why it would). :-O
> property. Or you can put some other property in
> the flash node for all I care, if that seems
> necessary for certain cases.
Erm... it's *certainly* necessary to mark this somewhere.
>>> The compatible is supposed to be useable to find and match a driver
>>> without regard to the name of the node. Perhaps direct-mapped-rom?
That really depends on whether we choose to follow the Generic Names spec.
Even if we do, it does *not* preclude OS from using both props for the driver
selection.
>>> (as opossed to a direct-mapped-ram, sram, or some width flash bank).
>> Note that we're matching by both "device_type" and "compatible".
> Which is wrong.
Why? And why then it's allowed to match by "device_type"? And why you
haven't complained at MPC5200 IDE driver which does the same (well, maybe you
have :-) or at PowerMac IDE driver which matches wither by "name" or
"device_type"? Well, quite a lot of drivers are doing this...
>> This would serve no purpose, as the driver that would catches all
>> these is signle one, drivers/mtd/maps/physmap_of.c...
> With the current kernel version, perhaps. Did you check
> out 2.6.28? Does it work with that?
For the simply mapped flashes, physmap_of will suffice, for more complex
cases, other driver will be needed. If you're hinting at the possibility that
MTD subsys will be substantially reworked -- I don't find that likely. If it
will -- well, bad luck. :-)
Anyway, reasonable suggestions on how to make MTD nodes more viable are
always welcome. I just haven't seen reasonable enough yet. ;-)
> Segher
WBR, Sergei
next prev parent reply other threads:[~2007-06-03 18:17 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-02 4:30 [PATCH] powerpc: Create "rom" (MTD) device prpmc2800 Milton Miller
2007-06-02 7:39 ` Benjamin Herrenschmidt
2007-06-03 16:10 ` Sergei Shtylyov
2007-06-03 17:36 ` Segher Boessenkool
2007-06-03 18:03 ` Sergei Shtylyov
2007-06-03 18:25 ` Segher Boessenkool
2007-06-03 18:36 ` Sergei Shtylyov
2007-06-03 18:46 ` Segher Boessenkool
2007-06-03 19:16 ` Sergei Shtylyov
2007-06-03 21:04 ` Benjamin Herrenschmidt
2007-06-04 12:34 ` Sergei Shtylyov
2007-06-04 14:37 ` Segher Boessenkool
2007-06-04 14:49 ` Sergei Shtylyov
2007-06-07 14:53 ` David Woodhouse
2007-06-07 15:49 ` Segher Boessenkool
2007-06-07 14:47 ` David Woodhouse
2007-06-07 15:32 ` Segher Boessenkool
2007-06-02 8:53 ` Segher Boessenkool
2007-06-03 16:22 ` Sergei Shtylyov
2007-06-03 17:40 ` Segher Boessenkool
2007-06-03 18:31 ` Sergei Shtylyov
2007-06-03 18:44 ` Segher Boessenkool
2007-06-03 19:13 ` Sergei Shtylyov
2007-06-03 19:56 ` Segher Boessenkool
2007-06-03 20:26 ` Sergei Shtylyov
2007-06-04 8:07 ` Segher Boessenkool
2007-06-04 13:34 ` Sergei Shtylyov
2007-06-07 15:00 ` David Woodhouse
2007-06-07 15:55 ` Segher Boessenkool
2007-06-07 16:05 ` David Woodhouse
2007-06-07 16:46 ` Segher Boessenkool
2007-06-12 4:44 ` David Gibson
2007-06-12 10:53 ` Segher Boessenkool
2007-06-13 3:16 ` David Gibson
2007-06-13 5:05 ` Segher Boessenkool
2007-06-13 6:11 ` David Gibson
2007-06-13 9:10 ` Segher Boessenkool
2007-06-15 4:12 ` David Gibson
2007-06-15 11:22 ` Segher Boessenkool
2007-06-15 4:14 ` David Gibson
2007-06-15 8:42 ` Segher Boessenkool
2007-06-15 8:47 ` David Woodhouse
2007-06-15 8:59 ` Segher Boessenkool
2007-06-03 21:12 ` Benjamin Herrenschmidt
2007-06-04 8:11 ` Segher Boessenkool
2007-06-04 13:16 ` Sergei Shtylyov
2007-06-04 12:41 ` Sergei Shtylyov
2007-06-04 14:49 ` Segher Boessenkool
2007-06-04 15:54 ` Sergei Shtylyov
2007-06-03 17:29 ` Sergei Shtylyov
2007-06-03 17:45 ` Segher Boessenkool
2007-06-03 18:18 ` Sergei Shtylyov [this message]
2007-06-03 18:43 ` Segher Boessenkool
2007-06-03 18:59 ` Sergei Shtylyov
2007-06-03 19:48 ` Segher Boessenkool
2007-06-03 20:10 ` Sergei Shtylyov
2007-06-04 8:02 ` Segher Boessenkool
2007-06-04 19:40 ` Mark A. Greer
-- strict thread matches above, loose matches on Subject: below --
2007-06-01 23:20 Mark A. Greer
2007-06-02 8:46 ` Segher Boessenkool
2007-06-04 20:56 ` Mark A. Greer
2007-06-05 20:35 ` Sergei Shtylyov
2007-06-05 21:11 ` Mark A. Greer
2007-06-06 12:41 ` Sergei Shtylyov
2007-06-07 15:08 ` David Woodhouse
2007-06-06 2:39 ` David Gibson
2007-06-07 13:30 ` Segher Boessenkool
2007-06-12 4:42 ` David Gibson
2007-06-12 10:50 ` Segher Boessenkool
2007-06-13 6:12 ` David Gibson
2007-06-13 9:13 ` Segher Boessenkool
2007-06-13 9:19 ` David Gibson
2007-06-13 9:37 ` Segher Boessenkool
2007-06-14 4:29 ` David Gibson
2007-06-14 8:00 ` Segher Boessenkool
2007-06-14 12:39 ` Sergei Shtylyov
2007-06-14 13:20 ` Segher Boessenkool
2007-06-14 12:48 ` Sergei Shtylyov
2007-06-14 13:18 ` Segher Boessenkool
2007-06-14 12:50 ` Sergei Shtylyov
2007-06-14 13:43 ` Segher Boessenkool
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