Re: [PATCH] unhide smbus on Compaq Deskpro EN

From: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
To: Krzysztof Helt <krzysztof.h1-5tc4TXWwyLM@public.gmane.org>
Cc: "Rafał Haładuda" <rh1985-5tc4TXWwyLM@public.gmane.org>,
	i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
Subject: Re: [PATCH] unhide smbus on Compaq Deskpro EN
Date: Wed, 4 Jun 2008 13:58:40 +0200	[thread overview]
Message-ID: <20080604135840.1c443824@hyperion.delvare> (raw)
In-Reply-To: <20080530232118.1b0078ff.krzysztof.h1-5tc4TXWwyLM@public.gmane.org>

On Fri, 30 May 2008 23:21:18 +0200, Krzysztof Helt wrote:
> From: Krzysztof Helt <krzysztof.h1@wp.pl>
> 
> This patch unhides the smbus on Compaq Deskpro EN
> SFF P667 with the Intel 815E chipset. 
> The patch was tested on Fedora Core 9 with 2.6.25.4 kernel.
> 
> Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
> Tested-by: Rafał Haładuda <rh1985@wp.pl>
> 
> ---
> 
> No side effects were observed. The ACPI controlled fan
> correctly with the patch applied. Tested with 667 and
> 1000 MHz CPUs.
> The patch allows using the THMC51 sensor chip on
> the motherboard.
> The patch was done against the kernel 2.6.26-rc2-mm1
> 
> diff -urp linux-2.6.25/drivers/pci/quirks.c linux-new/drivers/pci/quirks.c
> --- linux-2.6.25/drivers/pci/quirks.c	2008-05-27 21:58:34.380144607 +0200
> +++ linux-new/drivers/pci/quirks.c	2008-05-30 23:12:57.510219450 +0200
> @@ -1054,6 +1054,14 @@ static void __init asus_hides_smbus_host
>  				 * its on-board VGA controller */
>  				asus_hides_smbus = 1;
>  			}
> +		else if (dev->device == PCI_DEVICE_ID_INTEL_82815_CGC)
> +			switch (dev->subsystem_device) {
> +			case 0x001A: /* Compaq Deskpro EN ENS/P667/e */
> +				/* Motherboard doesn't have Host bridge
> +				 * subvendor/subdevice IDs, therefore checking
> +				 * its on-board VGA controller */
> +				asus_hides_smbus = 1;
> +			}
>  	}
>  }
>  DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82845_HB,	asus_hides_smbus_hostbridge);
> @@ -1068,6 +1076,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_I
>  DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82915GM_HB, asus_hides_smbus_hostbridge);
>  
>  DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82810_IG3,	asus_hides_smbus_hostbridge);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82815_CGC,	asus_hides_smbus_hostbridge);
>  
>  static void asus_hides_smbus_lpc(struct pci_dev *dev)
>  {

Patch looks OK, but it should be sent to the pci subsystem maintainer,
not me.

But first you want to double check that nothing wrong will happen. ACPI
looks OK but there is still the possibility of SMM quirks. To make sure,
you need to get your hands on the THMC51 datasheet and/or test if the
fan is self-regulated. And check if the low/high limits change over
time, too.

-- 
Jean Delvare

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