* [PATCH 0/1] tpm_tis: handle -EPROBE_DEFER in tpm_tis_plat_probe()
@ 2021-02-05 20:20 Dirk Gouders
2021-02-05 20:20 ` [PATCH 1/1] " Dirk Gouders
0 siblings, 1 reply; 3+ messages in thread
From: Dirk Gouders @ 2021-02-05 20:20 UTC (permalink / raw)
To: Peter Huewe, Jarkko Sakkinen, Jason Gunthorpe
Cc: Dirk Gouders, James Bottomley, linux-integrity, linux-kernel
Hello,
I noticed that the tpm_tis driver behaves different depending on
wether it was compiled builtin or as a module.
At least on my hardware, if builtin it always falls back to polling mode
without notification which I do not understand considering the current
efforts to fix interrupt probing[1].
The builtin case could be fixed by handling -EPROBE_DEFER. With a
temporary dev_dbg() call added and James Bottomley's
"[PATCH v2 4/5] tpm_tis: fix IRQ probing [1]" applied my kernel log
looks like this:
[ 2.671629] tpm_tis STM0125:00: Waiting for interrupt...
[ 2.851920] tpm_tis STM0125:00: Waiting for interrupt...
[ 2.852627] tpm_tis STM0125:00: Waiting for interrupt...
[ 2.908286] tpm_tis STM0125:00: Waiting for interrupt...
[ 3.340223] tpm_tis STM0125:00: Waiting for interrupt...
[ 3.407238] tpm_tis STM0125:00: Waiting for interrupt...
[ 3.408178] tpm_tis STM0125:00: Waiting for interrupt...
[ 3.408994] tpm_tis STM0125:00: Waiting for interrupt...
[ 3.487694] tpm_tis STM0125:00: Waiting for interrupt...
[ 3.773769] tpm_tis STM0125:00: Waiting for interrupt...
[ 3.868590] tpm_tis STM0125:00: Waiting for interrupt...
[ 3.923855] tpm_tis STM0125:00: Waiting for interrupt...
[ 4.235670] tpm_tis STM0125:00: Waiting for interrupt...
[ 4.852556] tpm_tis STM0125:00: Waiting for interrupt...
[ 6.767544] tpm_tis STM0125:00: 2.0 TPM (device-id 0x0, rev-id 78)
[ 6.767567] tpm_tis STM0125:00: TPM interface capabilities (0x30000415):
[ 6.767569] tpm_tis STM0125:00: Interrupt Level Low
[ 6.767570] tpm_tis STM0125:00: Locality Change Int Support
[ 6.767570] tpm_tis STM0125:00: Data Avail Int Support
Of course, this patch should not be added before Jarkko's fix [2], because
builtin drivers would then hit the WARN_ONCE(), as well.
Dirk
[1] https://lore.kernel.org/linux-integrity/20201001180925.13808-5-James.Bottomley@HansenPartnership.com/
[2] https://lore.kernel.org/linux-integrity/3936843b-c0da-dd8c-8aa9-90aa3b49d525@linux.ibm.com/T/#t
Dirk Gouders (1):
tpm_tis: handle -EPROBE_DEFER in tpm_tis_plat_probe()
drivers/char/tpm/tpm_tis.c | 3 +++
1 file changed, 3 insertions(+)
--
2.26.2
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 1/1] tpm_tis: handle -EPROBE_DEFER in tpm_tis_plat_probe()
2021-02-05 20:20 [PATCH 0/1] tpm_tis: handle -EPROBE_DEFER in tpm_tis_plat_probe() Dirk Gouders
@ 2021-02-05 20:20 ` Dirk Gouders
2021-02-08 0:41 ` Jarkko Sakkinen
0 siblings, 1 reply; 3+ messages in thread
From: Dirk Gouders @ 2021-02-05 20:20 UTC (permalink / raw)
To: Peter Huewe, Jarkko Sakkinen, Jason Gunthorpe
Cc: Dirk Gouders, James Bottomley, linux-integrity, linux-kernel
tpm_tis does not consider -EPROBE_DEFER in tpm_tis_plat_probe().
Instead, without notification it falls back to polling mode if
platform_get_irq_optional() returns a negative value.
This could lead to different behavior depending on wether tpm_tis was
compiled builtin or as a module; in the latter case
platform_get_irq_optional() often if not always returns a valid IRQ
number on the first attempt.
Harmonize builtin and module behavior by returning -EPROBE_DEFER,
effectively putting the device on the deferred probe list for later
probe attempts.
Signed-off-by: Dirk Gouders <dirk@gouders.net>
---
drivers/char/tpm/tpm_tis.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 4ed6e660273a..4cf863704aa1 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -320,6 +320,9 @@ static int tpm_tis_plat_probe(struct platform_device *pdev)
tpm_info.irq = platform_get_irq_optional(pdev, 0);
if (tpm_info.irq <= 0) {
+ if (tpm_info.irq == -EPROBE_DEFER)
+ /* Enter deferred probe list and try again, later. */
+ return -EPROBE_DEFER;
if (pdev != force_pdev)
tpm_info.irq = -1;
else
--
2.26.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 1/1] tpm_tis: handle -EPROBE_DEFER in tpm_tis_plat_probe()
2021-02-05 20:20 ` [PATCH 1/1] " Dirk Gouders
@ 2021-02-08 0:41 ` Jarkko Sakkinen
0 siblings, 0 replies; 3+ messages in thread
From: Jarkko Sakkinen @ 2021-02-08 0:41 UTC (permalink / raw)
To: Dirk Gouders
Cc: Peter Huewe, Jason Gunthorpe, James Bottomley, linux-integrity,
linux-kernel
On Fri, Feb 05, 2021 at 09:20:22PM +0100, Dirk Gouders wrote:
> tpm_tis does not consider -EPROBE_DEFER in tpm_tis_plat_probe().
> Instead, without notification it falls back to polling mode if
> platform_get_irq_optional() returns a negative value.
>
> This could lead to different behavior depending on wether tpm_tis was
> compiled builtin or as a module; in the latter case
> platform_get_irq_optional() often if not always returns a valid IRQ
> number on the first attempt.
>
> Harmonize builtin and module behavior by returning -EPROBE_DEFER,
> effectively putting the device on the deferred probe list for later
> probe attempts.
>
> Signed-off-by: Dirk Gouders <dirk@gouders.net>
This would be best picked to James' patch set.
> ---
> drivers/char/tpm/tpm_tis.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
> index 4ed6e660273a..4cf863704aa1 100644
> --- a/drivers/char/tpm/tpm_tis.c
> +++ b/drivers/char/tpm/tpm_tis.c
> @@ -320,6 +320,9 @@ static int tpm_tis_plat_probe(struct platform_device *pdev)
>
> tpm_info.irq = platform_get_irq_optional(pdev, 0);
> if (tpm_info.irq <= 0) {
> + if (tpm_info.irq == -EPROBE_DEFER)
> + /* Enter deferred probe list and try again, later. */
> + return -EPROBE_DEFER;
> if (pdev != force_pdev)
> tpm_info.irq = -1;
> else
> --
> 2.26.2
>
>
/Jarkko
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-02-05 20:20 [PATCH 0/1] tpm_tis: handle -EPROBE_DEFER in tpm_tis_plat_probe() Dirk Gouders
2021-02-05 20:20 ` [PATCH 1/1] " Dirk Gouders
2021-02-08 0:41 ` Jarkko Sakkinen
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