[PATCH] HID: intel-ish-hid: Prevent loading of driver on Mehlow

[PATCH] HID: intel-ish-hid: Prevent loading of driver on Mehlow

[Srinivas Pandruvada]

On Mehlow Xeon-E workstation, ISH PCI device is enabled but without ISH
firmware. Here the ISH device PCI device id was reused for some non Linux
storage drivers. So this was not done for enabling ISH. But this has a
undesirable side effect for Linux.

Here the ISH driver will be loaded via PCI enumeration and will try to do
reset sequence. But reset sequence will wait till timeout as there is no
real ISH firmware is present to take action. This delay will add to boot
time of Linux (This platform will still continue to boot after this
timeout).

To avoid this boot delay we need to prevent loading of ISH drivers on
this platform. So we need to have hack to avoid treating this device as
ISH on this platform. To identify this workstation, we need some runtime
method. Luckily there are special PCI id on this workstation to
distinguish from the client version of this platform. On client version,
the ISH is supported using same PCI device id. So this change look for
the presence of PCI device IDs A309 and A30A and exit.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
This is not a change for 4.18-rc.

 drivers/hid/intel-ish-hid/ipc/pci-ish.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/hid/intel-ish-hid/ipc/pci-ish.c b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
index a2c53ea3b5ed..d6e7156c36d9 100644
--- a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
+++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
@@ -95,6 +95,26 @@ static int ish_init(struct ishtp_device *dev)
 	return 0;
 }
 
+
+static bool ish_invalid_firmware(void)
+{
+	struct pci_dev *pdev;
+
+	pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0xA309, NULL);
+	if (pdev) {
+		pci_dev_put(pdev);
+		return true;
+	}
+
+	pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0xA30A, NULL);
+	if (pdev) {
+		pci_dev_put(pdev);
+		return true;
+	}
+
+	return false;
+}
+
 /**
  * ish_probe() - PCI driver probe callback
  * @pdev:	pci device
@@ -110,6 +130,9 @@ static int ish_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct ish_hw *hw;
 	int	ret;
 
+	if (ish_invalid_firmware())
+		return -ENODEV;
+
 	/* enable pci dev */
 	ret = pci_enable_device(pdev);
 	if (ret) {
-- 
2.17.1

Re: [PATCH] HID: intel-ish-hid: Prevent loading of driver on Mehlow

[Benjamin Tissoires]

On Tue, Jul 17, 2018 at 10:06 PM Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> wrote:
>
> On Mehlow Xeon-E workstation, ISH PCI device is enabled but without ISH
> firmware. Here the ISH device PCI device id was reused for some non Linux
> storage drivers. So this was not done for enabling ISH. But this has a
> undesirable side effect for Linux.
>
> Here the ISH driver will be loaded via PCI enumeration and will try to do
> reset sequence. But reset sequence will wait till timeout as there is no
> real ISH firmware is present to take action. This delay will add to boot
> time of Linux (This platform will still continue to boot after this
> timeout).
>
> To avoid this boot delay we need to prevent loading of ISH drivers on
> this platform. So we need to have hack to avoid treating this device as
> ISH on this platform. To identify this workstation, we need some runtime
> method. Luckily there are special PCI id on this workstation to
> distinguish from the client version of this platform. On client version,
> the ISH is supported using same PCI device id. So this change look for
> the presence of PCI device IDs A309 and A30A and exit.
>
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> ---
> This is not a change for 4.18-rc.
>
>  drivers/hid/intel-ish-hid/ipc/pci-ish.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>
> diff --git a/drivers/hid/intel-ish-hid/ipc/pci-ish.c b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> index a2c53ea3b5ed..d6e7156c36d9 100644
> --- a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> +++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> @@ -95,6 +95,26 @@ static int ish_init(struct ishtp_device *dev)
>         return 0;
>  }
>
> +
> +static bool ish_invalid_firmware(void)
> +{
> +       struct pci_dev *pdev;
> +
> +       pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0xA309, NULL);
> +       if (pdev) {
> +               pci_dev_put(pdev);
> +               return true;
> +       }
> +
> +       pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0xA30A, NULL);
> +       if (pdev) {
> +               pci_dev_put(pdev);
> +               return true;
> +       }

I think this duplicated code should be merged in a for loop on an
array of blacklisted items :)

Cheers,
Benjamin

> +
> +       return false;
> +}
> +
>  /**
>   * ish_probe() - PCI driver probe callback
>   * @pdev:      pci device
> @@ -110,6 +130,9 @@ static int ish_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>         struct ish_hw *hw;
>         int     ret;
>
> +       if (ish_invalid_firmware())
> +               return -ENODEV;
> +
>         /* enable pci dev */
>         ret = pci_enable_device(pdev);
>         if (ret) {
> --
> 2.17.1
>

Re: [PATCH] HID: intel-ish-hid: Prevent loading of driver on Mehlow

[Srinivas Pandruvada]

On Wed, 2018-07-18 at 09:53 +0200, Benjamin Tissoires wrote:
> On Tue, Jul 17, 2018 at 10:06 PM Srinivas Pandruvada
> <srinivas.pandruvada@linux.intel.com> wrote:
> > 
> > On Mehlow Xeon-E workstation, ISH PCI device is enabled but without
> > ISH
> > firmware. Here the ISH device PCI device id was reused for some non
> > Linux
> > storage drivers. So this was not done for enabling ISH. But this
> > has a
> > undesirable side effect for Linux.
> > 
> > Here the ISH driver will be loaded via PCI enumeration and will try
> > to do
> > reset sequence. But reset sequence will wait till timeout as there
> > is no
> > real ISH firmware is present to take action. This delay will add to
> > boot
> > time of Linux (This platform will still continue to boot after this
> > timeout).
> > 
> > To avoid this boot delay we need to prevent loading of ISH drivers
> > on
> > this platform. So we need to have hack to avoid treating this
> > device as
> > ISH on this platform. To identify this workstation, we need some
> > runtime
> > method. Luckily there are special PCI id on this workstation to
> > distinguish from the client version of this platform. On client
> > version,
> > the ISH is supported using same PCI device id. So this change look
> > for
> > the presence of PCI device IDs A309 and A30A and exit.
> > 
> > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel
> > .com>
> > ---
> > This is not a change for 4.18-rc.
> > 
> >  drivers/hid/intel-ish-hid/ipc/pci-ish.c | 23
> > +++++++++++++++++++++++
> >  1 file changed, 23 insertions(+)
> > 
> > diff --git a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> > b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> > index a2c53ea3b5ed..d6e7156c36d9 100644
> > --- a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> > +++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
> > @@ -95,6 +95,26 @@ static int ish_init(struct ishtp_device *dev)
> >         return 0;
> >  }
> > 
> > +
> > +static bool ish_invalid_firmware(void)
> > +{
> > +       struct pci_dev *pdev;
> > +
> > +       pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0xA309, NULL);
> > +       if (pdev) {
> > +               pci_dev_put(pdev);
> > +               return true;
> > +       }
> > +
> > +       pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0xA30A, NULL);
> > +       if (pdev) {
> > +               pci_dev_put(pdev);
> > +               return true;
> > +       }
> 
> I think this duplicated code should be merged in a for loop on an
> array of blacklisted items :)
Good idea.

Thanks,
Srinivas

> 
> Cheers,
> Benjamin
> 
> > +
> > +       return false;
> > +}
> > +
> >  /**
> >   * ish_probe() - PCI driver probe callback
> >   * @pdev:      pci device
> > @@ -110,6 +130,9 @@ static int ish_probe(struct pci_dev *pdev,
> > const struct pci_device_id *ent)
> >         struct ish_hw *hw;
> >         int     ret;
> > 
> > +       if (ish_invalid_firmware())
> > +               return -ENODEV;
> > +
> >         /* enable pci dev */
> >         ret = pci_enable_device(pdev);
> >         if (ret) {
> > --
> > 2.17.1
> >