On Fri, Jan 30, 2015 at 4:03 AM, Hans de Goede [off-list ref] wrote:

Hi,

On 01/29/2015 07:48 PM, Benjamin Tissoires wrote:

quoted

Hi Daniel,

in one hand I would like to see that upstream ASAP. But on the other
hand, I have some concerns here and there regarding this series.

On Tue, Jan 27, 2015 at 3:34 AM, Daniel Martin
[off-list ref] wrote:

quoted

From: Daniel Martin <redacted>

Query the min dimensions even if the check
    SYN_EXT_CAP_REQUESTS(priv->capabilities) >= 7
fails, but we know that the firmware version is safe. Atm. this is
version 8.1 only.

With that we don't need quirks for post-2013 models anymore as they
expose correct min and max dimensions.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=91541
Signed-off-by: Daniel Martin <redacted>
---
 drivers/input/mouse/synaptics.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index 7a78d75..37d4dff 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c

@@ -333,6 +333,30 @@ static int synaptics_identify(struct psmouse *psmouse)
        return -1;
 }

+struct fw_version {
+       unsigned char major;
+       unsigned char minor;
+};
+
+static const struct fw_version safe_fw_list[] = {
+       {8, 1}, /* safe for SYN_QUE_EXT_MIN_COORDS */
+       { }
+};
+
+static bool synaptics_is_safe_fw(struct psmouse *psmouse)
+{
+       struct synaptics_data *priv = psmouse->private;
+       int i;
+
+       for (i = 0; safe_fw_list[i].major; i++) {
+               if (safe_fw_list[i].major == SYN_ID_MAJOR(priv->identity) &&
+                   safe_fw_list[i].minor == SYN_ID_MINOR(priv->identity))
+                       return true;
+       }
+
+       return false;
+}

This seems a little bit too much for just one firmware ID.
Plus the name safe_fw_list gives hope that this list can be used for
something else later, but then it may conflict with it current
purpose.

How about we just rely on the current list of PNPIDs we already have
for this generation?
This might not be a good idea either, so an other solution would be to
directly check for firmware 8.1 in the test below.

I'd like to hear other opinions on this however before we commit to a decision.

I think that checking the firmware version, rather then relying on pnp-ids, is
the right thing to do, this e.g. also gives us more accurate min/max values
on the x230 / t430 series.

As for using the list, rather then just the one id, I'm fine either way, the list
is more future proof, which is why I acked this patch as is. But we could go
with just a check for the single version now and extend this later if needed.

If you are fine either way, I would lean to have only one check. I am
not confident in the "future proof" way of having a list, because the
list is too tight to the current bug. But I think I already made my
point clear enough.
Also, we already reported this to Synaptics, and I think (hope) they
will fix this in their future FW.

Cheers,
Benjamin