Messages in this thread | | | Date | Tue, 2 Feb 2021 18:17:34 +0200 | From | Jarkko Sakkinen <> | Subject | Re: [PATCH] tpm_tis: Add missing start/stop_tpm_chip calls |
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On Sat, Jan 30, 2021 at 04:41:13PM -0800, James Bottomley wrote: > On Sat, 2021-01-30 at 15:49 -0800, Guenter Roeck wrote: > > On 1/29/21 2:59 PM, Jarkko Sakkinen wrote: > > > On Tue, Jan 26, 2021 at 04:46:07PM +0100, Łukasz Majczak wrote: > > > > Hi Jarkko, Guenter > > > > > > > > Yes, here are the logs when failure occurs - > > > > https://gist.github.com/semihalf-majczak-lukasz/1575461f585f1e7fb1e9366b8eceaab9 > > > > Look for a phrase "TPM returned invalid status" > > > > > > > > Guenter - good suggestion - I will try to keep it as tight as > > > > possible. > > > > > > > > Best regards, > > > > Lukasz > > > > > > Is it possible for you try out with linux-next? Thanks. It's a > > > known issue, which ought to be fixed by now. > > > > > > The log message is harmless, it'a warning not panic, and does not > > > endanger system stability. WARN()'s always dump stack trace. No > > > oops is happening. > > > > > > > There is a note in the kernel documentation which states: > > > > Note that the WARN()-family should only be used for "expected to > > be unreachable" situations. If you want to warn about "reachable > > but undesirable" situations, please use the pr_warn()-family of > > functions. > > It fits the definition. The warning only triggers if the access is in > the wrong locality, which should be impossible, so the warning should > be unreachable.
It's an overkill. Even in perfectly working kernel it's not impossible, as sometimes hardware gives faulty data. I think that it also lacks the useful information i.e. the status code.
I would useful WARN() only if the driver state could suffer. In this case it doesn't. It only results failing transfer but kernel state is still legit.
/Jarkko >
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