Re: [tpmdd-devel] [PATCH] - TPM save state before suspending to ram

[David Smith <dds@google.com>]

[-- Attachment #1.1: Type: text/plain, Size: 2167 bytes --]

> On Fri 2008-01-04 14:09:01, Kent Yoder wrote:
> > On Jan 4, 2008 10:39 AM, Pavel Machek <pavel@ucw.cz> wrote:
> > > On Thu 2008-01-03 21:44:15, Marcel Selhorst wrote:
> > > > Dear list,
> > > >
> > > > this patch fixes a bug, that prevents the TPM chip to resume
> > > > correctly from a suspended state.
> > > >
> > > > Signed-off-by: Marcel Selhorst <tpm@selhorst.net>
> >
> > [cut]
> >
> > > I'm not sure if we want to use variable-size array on stack. What
> > > hacks are you doing with max_t/max?
> > >                                                                        
> > > Pavel
> >
> > Hi Pavel,
> >
> >   Here's an alternate solution from David, signoffs pending --
> >
> > commit 058f1e3c4d4e2de5a7188608a1c2e0722498fd4b
> > Author: David Smith <davidsmith@acm.org>
> > Date:   Fri Jan 4 03:33:11 2008 +0900
> >
> >     Fix for TPM suspend/resume failure
> >
> > diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
> > index 9bb5429..79d2fd5 100644
> > --- a/drivers/char/tpm/tpm.c
> > +++ b/drivers/char/tpm/tpm.c
> > @@ -1046,12 +1046,6 @@ void tpm_remove_hardware(struct device *dev)
> >  }
> >  EXPORT_SYMBOL_GPL(tpm_remove_hardware);
> >
> > -static u8 savestate[] = {
> > -	0, 193,			/* TPM_TAG_RQU_COMMAND */
> > -	0, 0, 0, 10,		/* blob length (in bytes) */
> > -	0, 0, 0, 152		/* TPM_ORD_SaveState */
> > -};
> > -
> >  /*
> >   * We are about to suspend. Save the TPM state
> >   * so that it can be restored.
> > @@ -1059,8 +1053,14 @@ static u8 savestate[] = {
> >  int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
> >  {
> >  	struct tpm_chip *chip = dev_get_drvdata(dev);
> > +        u8 savestate[] = {
> > +          0, 193,		/* TPM_TAG_RQU_COMMAND */
> > +          0, 0, 0, 10,		/* blob length (in bytes) */
> > +          0, 0, 0, 152		/* TPM_ORD_SaveState */
> > +        };
> > +
> >  	if (chip == NULL)
> > -		return -ENODEV;
> > +          return -ENODEV;
> >
> >  	tpm_transmit(chip, savestate, sizeof(savestate));
> >  	return 0;
>
> Yep, but please fix the whitespace.
> 									Pavel

OK, attached.
-- 
man perl | tail -6 | head -2

[-- Attachment #1.2: tpm-suspend.patch --]
[-- Type: text/x-diff, Size: 1320 bytes --]

commit a17f28b93a6e11097ea806d576eb317263aa8768
Author: David Smith <dds@toriatama.tok.corp.google.com>
Date:   Fri Jan 4 16:12:58 2008 +0900

    Fix TPM suspend and resume failure.
    
    The savestate command structure was being overwritten by the
    result of running the TPM_SaveState command after one run, so
    make it a local variable to the function instead of a global
    variable that gets overwritten.

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 9bb5429..4f18ddf 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1046,12 +1046,6 @@ void tpm_remove_hardware(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
 
-static u8 savestate[] = {
-	0, 193,			/* TPM_TAG_RQU_COMMAND */
-	0, 0, 0, 10,		/* blob length (in bytes) */
-	0, 0, 0, 152		/* TPM_ORD_SaveState */
-};
-
 /*
  * We are about to suspend. Save the TPM state
  * so that it can be restored.
@@ -1059,6 +1053,12 @@ static u8 savestate[] = {
 int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
 {
 	struct tpm_chip *chip = dev_get_drvdata(dev);
+	u8 savestate[] = {
+		0, 193,		/* TPM_TAG_RQU_COMMAND */
+		0, 0, 0, 10,	/* blob length (in bytes) */
+		0, 0, 0, 152	/* TPM_ORD_SaveState */
+	};
+
 	if (chip == NULL)
 		return -ENODEV;
 

[-- Attachment #2: This is a digitally signed message part. --]
[-- Type: application/pgp-signature, Size: 481 bytes --]