Messages in this thread | | | From | Christian Lamparter <> | Subject | Re: [RFC v2] lis3lv02d: avoid divide by zero due to unchecked register read | Date | Wed, 18 May 2011 18:03:08 +0200 |
| |
On Wednesday 18 May 2011 17:56:18 Éric Piel wrote: > Op 18-05-11 17:47, Christian Lamparter schreef: > > On Tuesday 17 May 2011 23:46:00 Éric Piel wrote: > >> Op 16-05-11 23:36, Christian Lamparter schreef: > >>> On Monday 16 May 2011 13:16:46 Éric Piel wrote: > >>> Do you know how "volatile" this data rate is? If it never changes > >>> [at least it doesn't here?] then why not read it once in init_device > >>> and store it in the device context? > >> It is not normally changing, normally it is set just at init/unsuspend > >> (where the bios can also interfere sometimes) and when the user changes > >> it. > > Uh, "bios can also interfere"... this sounds very bad. At least for > > my x41t the bios doesn't care about hdaps once the OS is running. > > > >> So definitely within the same function it's not going to suddenly > >> change. > > a SMM can happen at any time and if a faulty BIOS [likely, since I got > > a new laptop] is what caused the crash, I wouldn't bet on "const within > > a function context". > Yes, at least on the HP laptop I have the bios enjoys re-initialising > the hardware at some default value whenever suspend/resume happens. > > >> We could avoid calculating/checking it twice in > >> lis3lv02d_selftest(). Care to do a third version with this little clean up? > > I have my doubts, but ok if you say so... Just one thing: need to do some Q&A > > on the code above, I haven't tested it extensively yet. > I didn't know about the SMM... well, then let's keep the code as is. > > I'll try to test it on my laptop in the coming days. On which hardware > have you tested it? I've a dv6-6003eg, it's fairly new.
Regards, Chr -- 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/
| |