Messages in this thread | | | Subject | RE: [PATCH] [RESEND] Add Dell laptop backlight brightness display | Date | Mon, 20 Feb 2006 10:45:02 -0600 | From | <> |
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Pavel, Matthew has shown up on the libsmbios-devel mailing list. I sent all the info needed to do a test of Dell LCD brightness control. The main thing left would be to make one utility out of the current separate, unsupported, test utils.
As for fixing i8k, I don't have the slightest clue where to begin. You either have to split initialization with userspace to parse and send in the correct io/magic ports to do SMI, or you have to put Dell-specific SMI token parsing in the kernel.
If somebody wants to discuss the design, I can definetly discuss. I even have a _very_ rough mockup of userspace code to do this. Did not take it further because I don't know enough about lmsensors or how to fix i8k. -- Michael
PS> sorry for top-posting, my non-broken email client at home for some reason could not see your msg, so I could not reply from there.
-----Original Message----- From: Pavel Machek [mailto:pavel@ucw.cz] Sent: Sunday, February 12, 2006 11:26 AM To: Brown, Michael E Cc: mjg59@srcf.ucam.org; akpm@osdl.org; Domsch, Matt; linux-kernel@vger.kernel.org Subject: Re: [PATCH] [RESEND] Add Dell laptop backlight brightness display
Hi!
> You can get and set laptop brighness on Dell with the proper SMI call. > > To do the proper SMI call requires parsing SMBIOS structure 0xDA, a > vendor-proprietary structure, and getting the SMI index and io port > and magic values. Then, you need to know how to setup the registers > and input/output buffers for the call. All of this is already present > in libsmbios.
Perhaps authors of libsmbios could help here?
> Reading nvram is not a valid way to get brighness unless you also do > similar work (parse specific vendor-proprietary SMBIOS structures) to > ensure that you are reading the correct location. This location is > subject to change from BIOS to BIOS and machine to machine. The fact > that you may have observed it in the same location on a few laptops > does not change this fact.
Well, folks reverse-engineering your machines had no idea until now...
> In fact, I have the same objection to the I8K driver in the kernel. It
> has hardcoded SMI calls, that are subject to change. There is a proper
> way to get the correct IO ports to make this safe, but it is not > currently being done.
Could you or someone at Dell submit patches to correct this? -- 64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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