From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Sakkinen Subject: Re: [PATCH 2/3] tmp/tpm_crb: fix Intel PTT hw bug during idle state Date: Thu, 8 Sep 2016 14:14:58 +0300 Message-ID: <20160908111458.GE4712@intel.com> References: <1473247953-24617-1-git-send-email-tomas.winkler@intel.com> <1473247953-24617-3-git-send-email-tomas.winkler@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1473247953-24617-3-git-send-email-tomas.winkler-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tpmdd-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Tomas Winkler Cc: tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: tpmdd-devel@lists.sourceforge.net On Wed, Sep 07, 2016 at 02:32:32PM +0300, Tomas Winkler wrote: > There is a HW bug in Skylake, Kabylake, 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 I think I would add the dev_dbg line permanently with it that you have in responses in this thread. There's been some unrelated bugs before where this information in klog would have been very handy. Reviewed-by: Jarkko Sakkinen /Jarkko > --- > drivers/char/tpm/tpm_crb.c | 37 +++++++++++++++++++++++++++---------- > 1 file changed, 27 insertions(+), 10 deletions(-) > > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c > index 98a7fdfe9936..cf9aab698dfe 100644 > --- a/drivers/char/tpm/tpm_crb.c > +++ b/drivers/char/tpm/tpm_crb.c > @@ -328,6 +328,7 @@ 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; > @@ -335,15 +336,14 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, > int ret; > > INIT_LIST_HEAD(&resources); > - ret = acpi_dev_get_resources(device, &resources, crb_check_resource, > - &io_res); > + ret = acpi_dev_get_resources(device, &resources, > + crb_check_resource, &io_res); > if (ret < 0) > return ret; > acpi_dev_free_resource_list(&resources); > > if (resource_type(&io_res) != IORESOURCE_MEM) { > - dev_err(dev, > - FW_BUG "TPM2 ACPI table does not define a memory resource\n"); > + dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n"); > return -EINVAL; > } > > @@ -356,12 +356,24 @@ 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); > + > 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); > @@ -369,7 +381,8 @@ 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 > @@ -377,10 +390,14 @@ 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->rsp = priv->cmd; > + > +out: > + __crb_go_idle(dev, priv); > return 0; > } > > -- > 2.7.4 > ------------------------------------------------------------------------------