Re: [lm-sensors] 2.6.24-rc4 hwmon it87 probe fails

From: Shaohua Li
Date: Sun Dec 09 2007 - 21:32:19 EST



On Sun, 2007-12-09 at 23:04 +0100, Adrian Bunk wrote:
> On Sun, Dec 09, 2007 at 04:12:25PM -0500, Elvis Pranskevichus wrote:
> > Jean Delvare wrote:
> >
> > > Hi Mike,
> > >
> > > On Sat, 8 Dec 2007 21:22:34 -0500, Mike Houston wrote:
> > >> On Sun, 9 Dec 2007 01:05:54 +0100
> > >> Adrian Bunk <bunk@xxxxxxxxx> wrote:
> > >>
> > >> > On Tue, Dec 04, 2007 at 09:51:54PM -0500, Mike Houston wrote:
> > >> > > I finally got around to testing Linux 2.6.24 (2.6.24-rc4) and
> > >> > > found that the it87 driver fails to probe and consequently, my
> > >> > > sensors no longer work. This was fine with Linux 2.6.23.8 (the
> > >> > > last kernel I was using)
> > >> > >
> > >> > > The necessary modules load, but:
> > >> > >
> > >> > > it87: Found IT8718F chip at 0x290, revision 2
> > >> > > it87: in3 is VCC (+5V)
> > >> > > it87 it87.656: Failed to request region 0x290-0x297
> > >> > > it87: probe of it87.656 failed with error -16
> > >> > >
> > >> > > Coretemp still works.
> > >> > >
> > >> > > It appears it has something to do with the ioport range being
> > >> > > reserved for some reason:
> > >> > >
> > >> > > system 00:01: ioport range 0x290-0x29f has been reserved
> > >>
> > >> >
> > >> > Thanks for your report.
> > >> >
> > >> > Please also provide:
> > >> > - dmesg from 2.6.23.8
> > >> > - The output of "cat /proc/ioports" for both kernels
> > >>
> > >> Thanks Adrian, here is the information you have requested, for
> > >> both kernels (I have 2.6.23.9 now though where it87 still works)
> > >>
> > >> Linux 2.6.23.9:
> > >> http://www.mikeserv.com/temp/proc_ioports-2.6.23.9.txt
> > >> http://www.mikeserv.com/temp/dmesg-2.6.23.9.txt
> > >> http://www.mikeserv.com/temp/config-2.6.23.9.txt
> > >>
> > >> Linux 2.6.24-rc4:
> > >> http://www.mikeserv.com/temp/proc_ioports-2.6.24-rc4.txt
> > >> http://www.mikeserv.com/temp/dmesg-2.6.24-rc4.txt
> > >
> > > This one shows:
> > >
> > > system 00:01: ioport range 0x290-0x29f has been reserved
> > > (...)
> > > system 00:01: ioport range 0x290-0x294 has been reserved
> > >
> > > This is clearly not correct as both areas overlap. The second
> > > reservation is responsible for the it87 breakage, because it conflicts
> > > with what the it87 driver later attempts to request (0x290-0x297). The
> > > first is wrong as well (the IT87xxF environment controller I/O area is
> > > 8 port wide, not 16) but shouldn't be a problem in practice.
> > >
> > > These port reservations weren't happening in 2.6.23.9 according to your
> > > dmesg output for that kernel. I don't know what changed in this area
> > > since 2.6.23.9, maybe Bjorn or Adam (Cc'd) can tell.
> > >
> >
> > Hi,
> >
> > I have exactly the same problem here on a Gigabyte GA-965G-DS3 motherboard
> > based box:
> >
> > it87: Found IT8718F chip at 0x290, revision 1
> > it87: in3 is VCC (+5V)
> > it87 it87.656: Failed to request region 0x290-0x297
> > it87: probe of it87.656 failed with error -16
> >
> > git bisecting revealed the offending commit:
> >
> > a7839e960675b54: PNP: increase the maximum number of resources
> >
> > Happened between rc3 and rc4.
>
> Thanks for doing the work of bisecting!
>
> > > Either way, the overlapping areas smell like a BIOS bug, meaning that
> > > you should look for an updated BIOS for your system first.
> > >
> > >> http://www.mikeserv.com/temp/config-2.6.24-rc4.txt
> > >
> >
> > This indeed looks like a broken ACPI BIOS since the aforementioned commit
> > touches only the PNP ACPI driver. I'm not sure how to work around this,
> > though. Ideas?
>
> People responsible for this commit + ACPI maintainer added to Cc.
This should exist in previous kernel (before we remove acpi motherboard
driver) too. Basically it's a broken BIOS. Could below patch work around
it?

Thanks,
Shaohua

Index: linux/drivers/pnp/system.c
===================================================================
--- linux.orig/drivers/pnp/system.c 2007-12-10 10:17:46.000000000 +0800
+++ linux/drivers/pnp/system.c 2007-12-10 10:24:42.000000000 +0800
@@ -22,7 +22,7 @@ static const struct pnp_device_id pnp_de
{"", 0}
};

-static void reserve_range(struct pnp_dev *dev, resource_size_t start,
+static struct resource* reserve_range(struct pnp_dev *dev, resource_size_t start,
resource_size_t end, int port)
{
char *regionid;
@@ -31,16 +31,14 @@ static void reserve_range(struct pnp_dev

regionid = kmalloc(16, GFP_KERNEL);
if (!regionid)
- return;
+ return NULL;

snprintf(regionid, 16, "pnp %s", pnpid);
if (port)
res = request_region(start, end - start + 1, regionid);
else
res = request_mem_region(start, end - start + 1, regionid);
- if (res)
- res->flags &= ~IORESOURCE_BUSY;
- else
+ if (!res)
kfree(regionid);

/*
@@ -52,12 +50,17 @@ static void reserve_range(struct pnp_dev
port ? "ioport" : "iomem",
(unsigned long long) start, (unsigned long long) end,
res ? "has been" : "could not be");
+ return res;
}

static void reserve_resources_of_dev(struct pnp_dev *dev)
{
int i;
+ struct resource **res;

+ res = kzalloc(sizeof(struct resource *) * PNP_MAX_PORT, GFP_KERNEL);
+ if (!res)
+ return;
for (i = 0; i < PNP_MAX_PORT; i++) {
if (!pnp_port_valid(dev, i))
continue;
@@ -76,17 +79,28 @@ static void reserve_resources_of_dev(str
if (pnp_port_end(dev, i) < pnp_port_start(dev, i))
continue; /* invalid */

- reserve_range(dev, pnp_port_start(dev, i),
+ res[i] = reserve_range(dev, pnp_port_start(dev, i),
pnp_port_end(dev, i), 1);
}
+ for (i = 0; i < PNP_MAX_PORT; i++)
+ if (res[i])
+ res[i]->flags &= ~IORESOURCE_BUSY;
+ kfree(res);

+ res = kzalloc(sizeof(struct resource *) * PNP_MAX_MEM, GFP_KERNEL);
+ if (!res)
+ return;
for (i = 0; i < PNP_MAX_MEM; i++) {
if (!pnp_mem_valid(dev, i))
continue;

- reserve_range(dev, pnp_mem_start(dev, i),
+ res[i] = reserve_range(dev, pnp_mem_start(dev, i),
pnp_mem_end(dev, i), 0);
}
+ for (i = 0; i < PNP_MAX_MEM; i++)
+ if (res[i])
+ res[i]->flags &= ~IORESOURCE_BUSY;
+ kfree(res);
}

static int system_pnp_probe(struct pnp_dev *dev,
--
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