* Re: tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0
@ 2015-10-20 11:49 Andreas Ziegler
2015-10-20 14:58 ` Jarkko Sakkinen
0 siblings, 1 reply; 4+ messages in thread
From: Andreas Ziegler @ 2015-10-20 11:49 UTC (permalink / raw)
To: Jarkko Sakkinen
Cc: Peter Huewe, Marcel Selhorst, Jason Gunthorpe, tpmdd-devel,
linux-kernel@vger.kernel.org, Valentin Rothberg, Paul Bolle
Hi Jarkko,
your patch "tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0"
showed up as commit 399235dc6e95 in linux-next today (that is,
next-20151020). I noticed it because we (a research group from
Erlangen[0]) are running daily checks on linux-next.
Your commit creates the following structure of #ifdef blocks in
drivers/char/tpm/tpm_tis.c following line 1088:
#ifdef CONFIG_ACPI
...
#ifdef CONFIG_PNP
...
#endif
...
#endif
Looking at the definition of CONFIG_ACPI at drivers/acpi/Kconfig, line
5, we see that ACPI unconditionally selects PNP, meaning that CONFIG_PNP
is always enabled if CONFIG_ACPI has been enabled.
Thus, the inner #ifdef statement can never evaluate to 'false' if the
outer #ifdef evaluates to true (i.e., CONFIG_ACPI is enabled), and
hence, the #ifdef is unnecessary.
The same situation holds for the nested structure following line 1124,
where the #ifdef CONFIG_PNP at line 1129 is unnecessary.
Is this correct or did we miss something?
Regards,
Andreas
[0] https://cados.cs.fau.de
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0
2015-10-20 11:49 tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0 Andreas Ziegler
@ 2015-10-20 14:58 ` Jarkko Sakkinen
2015-10-21 15:58 ` [tpmdd-devel] " Jarkko Sakkinen
0 siblings, 1 reply; 4+ messages in thread
From: Jarkko Sakkinen @ 2015-10-20 14:58 UTC (permalink / raw)
To: Andreas Ziegler
Cc: Peter Huewe, Marcel Selhorst, Jason Gunthorpe, tpmdd-devel,
linux-kernel@vger.kernel.org, Valentin Rothberg, Paul Bolle
On Tue, Oct 20, 2015 at 01:49:02PM +0200, Andreas Ziegler wrote:
> Hi Jarkko,
>
> your patch "tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0"
> showed up as commit 399235dc6e95 in linux-next today (that is,
> next-20151020). I noticed it because we (a research group from
> Erlangen[0]) are running daily checks on linux-next.
>
> Your commit creates the following structure of #ifdef blocks in
> drivers/char/tpm/tpm_tis.c following line 1088:
>
> #ifdef CONFIG_ACPI
> ...
> #ifdef CONFIG_PNP
> ...
> #endif
> ...
> #endif
>
> Looking at the definition of CONFIG_ACPI at drivers/acpi/Kconfig, line
> 5, we see that ACPI unconditionally selects PNP, meaning that CONFIG_PNP
> is always enabled if CONFIG_ACPI has been enabled.
> Thus, the inner #ifdef statement can never evaluate to 'false' if the
> outer #ifdef evaluates to true (i.e., CONFIG_ACPI is enabled), and
> hence, the #ifdef is unnecessary.
>
> The same situation holds for the nested structure following line 1124,
> where the #ifdef CONFIG_PNP at line 1129 is unnecessary.
>
> Is this correct or did we miss something?
Good catch. Shoud I send a separate fix for this? Thanks for pointing
this out.
> Regards,
>
> Andreas
>
> [0] https://cados.cs.fau.de
/Jarkko
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [tpmdd-devel] tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0
2015-10-20 14:58 ` Jarkko Sakkinen
@ 2015-10-21 15:58 ` Jarkko Sakkinen
2015-10-23 13:01 ` Valentin Rothberg
0 siblings, 1 reply; 4+ messages in thread
From: Jarkko Sakkinen @ 2015-10-21 15:58 UTC (permalink / raw)
To: Andreas Ziegler
Cc: Paul Bolle, Valentin Rothberg, linux-kernel@vger.kernel.org,
tpmdd-devel
On Tue, Oct 20, 2015 at 05:58:35PM +0300, Jarkko Sakkinen wrote:
> On Tue, Oct 20, 2015 at 01:49:02PM +0200, Andreas Ziegler wrote:
> > Hi Jarkko,
> >
> > your patch "tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0"
> > showed up as commit 399235dc6e95 in linux-next today (that is,
> > next-20151020). I noticed it because we (a research group from
> > Erlangen[0]) are running daily checks on linux-next.
> >
> > Your commit creates the following structure of #ifdef blocks in
> > drivers/char/tpm/tpm_tis.c following line 1088:
> >
> > #ifdef CONFIG_ACPI
> > ...
> > #ifdef CONFIG_PNP
> > ...
> > #endif
> > ...
> > #endif
> >
> > Looking at the definition of CONFIG_ACPI at drivers/acpi/Kconfig, line
> > 5, we see that ACPI unconditionally selects PNP, meaning that CONFIG_PNP
> > is always enabled if CONFIG_ACPI has been enabled.
> > Thus, the inner #ifdef statement can never evaluate to 'false' if the
> > outer #ifdef evaluates to true (i.e., CONFIG_ACPI is enabled), and
> > hence, the #ifdef is unnecessary.
> >
> > The same situation holds for the nested structure following line 1124,
> > where the #ifdef CONFIG_PNP at line 1129 is unnecessary.
> >
> > Is this correct or did we miss something?
>
> Good catch. Shoud I send a separate fix for this? Thanks for pointing
> this out.
In all I would cases do a separate fix and do not fixup the original
patchs because I wouldn't consider this a regression.
The next question is: will it always be like this? Can I safely assume
that ACPI will always select PNP unconditionally? This is so minor
cosmetic glitch in the code that I'm getting second thoughts whether I
should anything to this or not.
/Jarkko
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [tpmdd-devel] tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0
2015-10-21 15:58 ` [tpmdd-devel] " Jarkko Sakkinen
@ 2015-10-23 13:01 ` Valentin Rothberg
0 siblings, 0 replies; 4+ messages in thread
From: Valentin Rothberg @ 2015-10-23 13:01 UTC (permalink / raw)
To: Jarkko Sakkinen
Cc: Andreas Ziegler, Paul Bolle, linux-kernel@vger.kernel.org,
tpmdd-devel
On Oct 21 '15 18:58, Jarkko Sakkinen wrote:
> On Tue, Oct 20, 2015 at 05:58:35PM +0300, Jarkko Sakkinen wrote:
> > On Tue, Oct 20, 2015 at 01:49:02PM +0200, Andreas Ziegler wrote:
> > > Hi Jarkko,
> > >
> > > your patch "tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0"
> > > showed up as commit 399235dc6e95 in linux-next today (that is,
> > > next-20151020). I noticed it because we (a research group from
> > > Erlangen[0]) are running daily checks on linux-next.
> > >
> > > Your commit creates the following structure of #ifdef blocks in
> > > drivers/char/tpm/tpm_tis.c following line 1088:
> > >
> > > #ifdef CONFIG_ACPI
> > > ...
> > > #ifdef CONFIG_PNP
> > > ...
> > > #endif
> > > ...
> > > #endif
> > >
> > > Looking at the definition of CONFIG_ACPI at drivers/acpi/Kconfig, line
> > > 5, we see that ACPI unconditionally selects PNP, meaning that CONFIG_PNP
> > > is always enabled if CONFIG_ACPI has been enabled.
> > > Thus, the inner #ifdef statement can never evaluate to 'false' if the
> > > outer #ifdef evaluates to true (i.e., CONFIG_ACPI is enabled), and
> > > hence, the #ifdef is unnecessary.
> > >
> > > The same situation holds for the nested structure following line 1124,
> > > where the #ifdef CONFIG_PNP at line 1129 is unnecessary.
> > >
> > > Is this correct or did we miss something?
> >
> > Good catch. Shoud I send a separate fix for this? Thanks for pointing
> > this out.
>
> In all I would cases do a separate fix and do not fixup the original
> patchs because I wouldn't consider this a regression.
>
> The next question is: will it always be like this? Can I safely assume
> that ACPI will always select PNP unconditionally? This is so minor
> cosmetic glitch in the code that I'm getting second thoughts whether I
> should anything to this or not.
Any option has certain benefits. In the current form, a reader might
(falsely) assume that the block is configurable. However, if the
constraints of ACPI or PNP change, the situation might look different.
Best regards,
Valentin
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-10-23 13:08 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2015-10-20 11:49 tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0 Andreas Ziegler
2015-10-20 14:58 ` Jarkko Sakkinen
2015-10-21 15:58 ` [tpmdd-devel] " Jarkko Sakkinen
2015-10-23 13:01 ` Valentin Rothberg
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