On 23/08/16 15:55, Neil Armstrong wrote:

On 08/23/2016 04:54 PM, Sudeep Holla wrote:

quoted

On 23/08/16 09:23, Neil Armstrong wrote:

quoted

On 08/19/2016 06:46 PM, Sudeep Holla wrote:

quoted

On 18/08/16 11:11, Neil Armstrong wrote:

quoted

In Amlogic GXBB Legacy SCPI, the LEGACY_SCPI_CMD_SCPI_CAPABILITIES report
as SCPI_ERR_SUPPORT, so do not fail if this command is not supported.

Signed-off-by: Neil Armstrong <redacted>
---
 drivers/firmware/arm_scpi.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/firmware/arm_scpi.c b/drivers/firmware/arm_scpi.c
index 3fe39fe..d3be4c5 100644
--- a/drivers/firmware/arm_scpi.c
+++ b/drivers/firmware/arm_scpi.c

@@ -1111,12 +1111,13 @@ err:
         ret = scpi_info->ops->init_versions(scpi_info);
     else
     ret = scpi_init_versions(scpi_info);
-    if (ret) {
+    if (ret && ret != -EOPNOTSUPP) {
         dev_err(dev, "incorrect or no SCP firmware found\n");
         scpi_remove(pdev);
         return ret;
     }

Why not deal it in init_versions itself.

quoted

+    if (ret != -EOPNOTSUPP) {
     _dev_info(dev, "SCP Protocol %d.%d Firmware %d.%d.%d version\n",
           PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
           PROTOCOL_REV_MINOR(scpi_info->protocol_version),

Why not have default value like 0.0 ? Just add a comment. Since get
version is exported out, IMO having default value makes more sense. What
do you think ?

quoted

@@ -1124,15 +1125,16 @@ err:
           FW_REV_MINOR(scpi_info->firmware_version),
           FW_REV_PATCH(scpi_info->firmware_version));

+        ret = sysfs_create_groups(&dev->kobj, versions_groups);
+        if (ret)
+            dev_err(dev, "unable to create sysfs version group\n");
+    }
+

Again this can stay as is if we have default.

Printing version 0.0 firmware 0.0.0 is a nonsense for me...

OK 0.0 was a wrong example. May be 0.1 ?

Since the driver has already exposed, hypothetically user-space can use
that information, so IMO, we need to expose some static version for pre-v1.0

I am surprised that capability is not supported as this was present even
in that legacy SCPI. Do you know what happens if you send that command ?
Have you done some experiments on that ?

I've experimented and returns EOPNOTSUPP, Amlogic confirmed to us the command was not implemented.

This a clearly a corner-case.

OK, thanks for the confirmation.
Not exporting anything could be kind of breaking ABI as it was not made
optional when introduced :( (you can blame me ;))

-- 
Regards,
Sudeep