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From: Hans de Goede <j.w.r.degoede@hhs•nl>
To: Milton Miller <miltonm@bga•com>
Cc: linuxppc-dev@ozlabs•org, Samuel Ortiz <samuel@sortiz•org>,
	linux-kernel@vger•kernel.org, lm-sensors@lm-sensors•org
Subject: Re: [lm-sensors] [RFC] (almost) booting allyesconfig -- please don't poke super-io without request_region
Date: Thu, 10 Jul 2008 23:33:12 +0200	[thread overview]
Message-ID: <48768018.2070704@hhs.nl> (raw)
In-Reply-To: <for-27-patch1-0@bga.com>

Milton Miller wrote:
> After the following patch to mark the isa region busy and applying a few
> patches[1], I was able to kexec boot into an all-yes-config kernel from 
> linux-next, with the following KCONFIG_ALLCONFIG file:
> 
> # CONFIG_KALLSYMS_EXTRA_PASS is not set
> # CONFIG_CRASH_DUMP is not set
> CONFIG_PPC_EARLY_DEBUG_RTAS_CONSOLE=y
> # CONFIG_NSC_FIR is not set
> # CONFIG_SMC_IRCC_FIR is not set
> # CONFIG_ALI_FIR is not set
> # CONFIG_TCG_NSC is not set
> # CONFIG_TCG_ATMEL is not set
> # CONFIG_SENSORS_F71805F is not set
> # CONFIG_SENSORS_F71882FG is not set
> # CONFIG_SENSORS_F75375S is not set
> # CONFIG_SENSORS_IT87 is not set
> # CONFIG_SENSORS_PC87360 is not set
> # CONFIG_SENSORS_PC87427 is not set
> # CONFIG_SENSORS_DME1737 is not set
> # CONFIG_SENSORS_SMSC47M1 is not set
> # CONFIG_SENSORS_SMSC47B397 is not set
> # CONFIG_SENSORS_VT1211 is not set
> # CONFIG_SENSORS_W83627HF is not set
> # CONFIG_SENSORS_W83627EHF is not set
> 
> While the first two might not be required, and the third is just
> selecting the right platform, it would be nice to get the drivers
> to play as well as the rest of the kernel.
> 
> The drivers all are for super-io chips, either irda/FIR drivers or hwmon,
> and poke at isa ports without checking request_region.
> 

Erm,

The superio sensor drivers only poke the superio chip registers without request 
region during the probe phase, iow they try to detect the chip, using a widely 
document and standardized (part of isa pnp AFAIK) procedure on standardized ports.

Let me try to explain a bit about superio chips, they have 2 superio control 
registers (an index and data register) with which things like a manufacturer 
and device id can be read, besides these id registers they also have a set of 
registers with config for different logical devices. Once the id is matched, 
the driver knows which logical device config to read, reads a (different) isa 
base address + range from the logical device config, and then does a 
request_region on the region actually used by the logical device.

The superio control registers are thus a sort of pci configuration space if you 
want, doing a request_region on these is not such a good idea, as multiple 
drivers (for different logical devices within the superio device) may use 
these, so trying to gain exclusive access will lead to troubles.

I hope with this info about the problem space, that you maybe have a suggestion 
on howto fix this?

Regards,

Hans
> 

  parent reply	other threads:[~2008-07-10 21:32 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-10 21:12 [RFC] (almost) booting allyesconfig -- please don't poke super-io without request_region Milton Miller
2008-07-10 21:14 ` mtd: remove __PPC__ hardcoded address from nand/diskonchip and devices/docprobe Milton Miller
2008-07-10 21:14 ` [1/3] powerpc: add _HEAD_GLOBAL to place functions in .text.head Milton Miller
2008-07-10 21:16 ` [2/3] powerpc: head_64.S: put irq vectors " Milton Miller
2008-07-10 21:19 ` powerpc: numa.c: always trim to lmb_end_of_DRAM Milton Miller
2008-07-10 21:20 ` powerpc: pseries, cell: use cpu_thread_in_core in smp_init for of_spin_map Milton Miller
2008-07-10 21:22 ` powerpc: find and destroy possible stale kernel added properties Milton Miller
2008-07-10 21:23 ` powerpc: add static and ifdef prom_strtoul and prom_memparse Milton Miller
2008-07-10 21:29 ` [PATCH] spufs: correct kcalloc usage Milton Miller
2008-07-10 23:04   ` Jeremy Kerr
2008-07-10 21:33 ` Hans de Goede [this message]
2008-07-10 21:51   ` [lm-sensors] [RFC] (almost) booting allyesconfig -- please don't poke super-io without request_region Milton Miller
2008-07-11  6:52     ` Jean Delvare
2008-07-11  7:27       ` Hans de Goede
2008-07-11  7:36         ` Jean Delvare
2008-07-13  6:31           ` Hans de Goede
2008-07-13 21:11             ` [lm-sensors] " David Hubbard
2008-07-13 21:22               ` Hans de Goede
2008-07-13 21:26                 ` David Hubbard
2008-07-14  7:59                   ` Jean Delvare
2008-07-14 17:09                     ` Milton Miller
2008-07-14 17:30                       ` [lm-sensors] " Hans de Goede
2008-07-14 17:55                         ` David Hubbard
2008-07-15  8:36                           ` Jean Delvare
2008-07-15 15:31                             ` David Hubbard
2008-07-16  7:46                               ` Jean Delvare
2008-07-16  8:09                                 ` Rene Herman
2008-07-15  8:28                       ` Jean Delvare

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