Re: [PATCH 0/2] Revert patches fixing probing of interrupts

[Jerry Snitselaar]

On Mon Dec 09 19, Jarkko Sakkinen wrote:
> On Mon, Dec 02, 2019 at 11:55:20AM -0700, Jerry Snitselaar wrote:
> > On Sun Dec 01 19, Stefan Berger wrote:
> > > On 11/29/19 5:37 PM, Jarkko Sakkinen wrote:
> > > > On Tue, Nov 26, 2019 at 08:17:51AM -0500, Stefan Berger wrote:
> > > > > From: Stefan Berger <stefanb@xxxxxxxxxxxxx>
> > > > >
> > > > > Revert the patches that were fixing the probing of interrupts due
> > > > > to reports of interrupt stroms on some systems
> > > > Can you explain how reverting is going to fix the issue?
> > >
> > >
> > > The reverts fix 'the interrupt storm issue' that they are causing on
> > > some systems but don't fix the issue with the interrupt mode not being
> > > used. I was hoping Jerry would get access to a system faster but this
> > > didn't seem to be the case. So sending these patches seemed the better
> > > solution than leaving 5.4.x with the problem but going back to when it
> > > worked 'better.'
> > >
> >
> > I finally heard back from IT support, and unfortunately they don't
> > have any T490s systems to give out on temp loan. So I can only send
> > patched kernels to the end user that had the problem.
>
> At least it is a fact that tpm_chip_stop() is called too early and that
> is destined to cause issues.
>
> Should I bake a patch or do you have already something?
>
> /Jarkko

This is what I'm currently building:

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 270f43acbb77..17184c07eb51 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -899,13 +899,13 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 
 	if (wait_startup(chip, 0) != 0) {
 		rc = -ENODEV;
-		goto out_err;
+		goto out_start;
 	}
 
 	/* Take control of the TPM's interrupt hardware and shut it off */
 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
 	if (rc < 0)
-		goto out_err;
+		goto out_start;
 
 	intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
 		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
@@ -914,9 +914,8 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 
 	rc = tpm_chip_start(chip);
 	if (rc)
-		goto out_err;
+		goto out_start;
 	rc = tpm2_probe(chip);
-	tpm_chip_stop(chip);
 	if (rc)
 		goto out_err;
 
@@ -980,7 +979,6 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 			goto out_err;
 		}
 
-		tpm_chip_start(chip);
 		chip->flags |= TPM_CHIP_FLAG_IRQ;
 		if (irq) {
 			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
@@ -991,18 +989,17 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 		} else {
 			tpm_tis_probe_irq(chip, intmask);
 		}
-		tpm_chip_stop(chip);
 	}
+	tpm_chip_stop(chip);
 
 	rc = tpm_chip_register(chip);
 	if (rc)
-		goto out_err;
-
-	if (chip->ops->clk_enable != NULL)
-		chip->ops->clk_enable(chip, false);
+		goto out_start;
 
 	return 0;
 out_err:
+	tpm_chip_stop(chip);
+out_start:
 	if ((chip->ops != NULL) && (chip->ops->clk_enable != NULL))
 		chip->ops->clk_enable(chip, false);