On Mon, Sep 12, 2016 at 04:04:19PM +0300, Tomas Winkler wrote: > There is a HW bug in Skylake, and Broxton PCH Intel PTT device, where > most of the registers in the control area except START, REQUEST, CANCEL, > and LOC_CTRL lost retention when the device is in the idle state. Hence > we need to bring the device to ready state before accessing the other > registers. The fix brings device to ready state before trying to read > command and response buffer addresses in order to remap the for access. > > Signed-off-by: Tomas Winkler <[email protected]>
Tested-by: Jarkko Sakkinen <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> /Jarkko > --- > V2: cmd read need to be called also before crb_init as this will run > self test. > V3: resend. > > drivers/char/tpm/tpm_crb.c | 47 > ++++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 39 insertions(+), 8 deletions(-) > > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c > index b6923a8b3ff7..e945177cf2c8 100644 > --- a/drivers/char/tpm/tpm_crb.c > +++ b/drivers/char/tpm/tpm_crb.c > @@ -318,6 +318,7 @@ static int crb_map_io(struct acpi_device *device, struct > crb_priv *priv, > struct list_head resources; > struct resource io_res; > struct device *dev = &device->dev; > + u32 pa_high, pa_low; > u64 cmd_pa; > u32 cmd_size; > u64 rsp_pa; > @@ -345,12 +346,27 @@ static int crb_map_io(struct acpi_device *device, > struct crb_priv *priv, > if (IS_ERR(priv->cca)) > return PTR_ERR(priv->cca); > > - cmd_pa = ((u64) ioread32(&priv->cca->cmd_pa_high) << 32) | > - (u64) ioread32(&priv->cca->cmd_pa_low); > + /* > + * PTT HW bug w/a: wake up the device to access > + * possibly not retained registers. > + */ > + ret = crb_cmd_ready(dev, priv); > + if (ret) > + return ret; > + > + pa_high = ioread32(&priv->cca->cmd_pa_high); > + pa_low = ioread32(&priv->cca->cmd_pa_low); > + cmd_pa = ((u64)pa_high << 32) | pa_low; > cmd_size = ioread32(&priv->cca->cmd_size); > + > + dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n", > + pa_high, pa_low, cmd_size); > + > priv->cmd = crb_map_res(dev, priv, &io_res, cmd_pa, cmd_size); > - if (IS_ERR(priv->cmd)) > - return PTR_ERR(priv->cmd); > + if (IS_ERR(priv->cmd)) { > + ret = PTR_ERR(priv->cmd); > + goto out; > + } > > memcpy_fromio(&rsp_pa, &priv->cca->rsp_pa, 8); > rsp_pa = le64_to_cpu(rsp_pa); > @@ -358,7 +374,8 @@ static int crb_map_io(struct acpi_device *device, struct > crb_priv *priv, > > if (cmd_pa != rsp_pa) { > priv->rsp = crb_map_res(dev, priv, &io_res, rsp_pa, rsp_size); > - return PTR_ERR_OR_ZERO(priv->rsp); > + ret = PTR_ERR_OR_ZERO(priv->rsp); > + goto out; > } > > /* According to the PTP specification, overlapping command and response > @@ -366,12 +383,18 @@ static int crb_map_io(struct acpi_device *device, > struct crb_priv *priv, > */ > if (cmd_size != rsp_size) { > dev_err(dev, FW_BUG "overlapping command and response buffer > sizes are not identical"); > - return -EINVAL; > + ret = -EINVAL; > + goto out; > } > + > priv->cmd_size = cmd_size; > > priv->rsp = priv->cmd; > - return 0; > + > +out: > + crb_go_idle(dev, priv); > + > + return ret; > } > > static int crb_acpi_add(struct acpi_device *device) > @@ -415,7 +438,15 @@ static int crb_acpi_add(struct acpi_device *device) > if (rc) > return rc; > > - return crb_init(device, priv); > + rc = crb_cmd_ready(dev, priv); > + if (rc) > + return rc; > + > + rc = crb_init(device, priv); > + if (rc) > + crb_go_idle(dev, priv); > + > + return rc; > } > > static int crb_acpi_remove(struct acpi_device *device) > -- > 2.7.4 > ------------------------------------------------------------------------------ _______________________________________________ tpmdd-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/tpmdd-devel
