Hi Enrico,
Many thanks to send this upstream.
On 4/4/19 18:00, Jett ✈ Rink wrote:
> Reviewed-by: Jett Rink <jettr...@chromium.org>
>
> On Wed, Apr 3, 2019 at 4:40 PM <egran...@chromium.org> wrote:
>>
>> From: Enrico Granata <egran...@chromium.org>
>>
>> As new transfer mechanisms are added to the EC codebase, they may
>> not support v2 of the EC protocol.
>>
>> If the v3 initial handshake transfer fails, the kernel will try
>> and call cmd_xfer as a fallback. If v2 is not supported, cmd_xfer
>> will be NULL, and the code will end up causing a kernel panic.
>>
>> Add a check for NULL before calling the transfer function, along
>> with a helpful comment explaining how one might end up in this
>> situation.
>>
>> Signed-off-by: Enrico Granata <egran...@chromium.org>
>> ---
>> drivers/platform/chrome/cros_ec_proto.c | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/platform/chrome/cros_ec_proto.c
>> b/drivers/platform/chrome/cros_ec_proto.c
>> index 97a068dff192d..55691656a3c27 100644
>> --- a/drivers/platform/chrome/cros_ec_proto.c
>> +++ b/drivers/platform/chrome/cros_ec_proto.c
>> @@ -56,6 +56,16 @@ static int send_command(struct cros_ec_device *ec_dev,
>> else
>> xfer_fxn = ec_dev->cmd_xfer;
>>
>> + if (xfer_fxn == NULL) {
>> + /* This error can happen if a communication error happened
>> and
Like Guenter I personally don't like the networking-style multi-line comments.
We try to use the default kernel-style so if you don't mind I'll change this.
>> + * the EC is trying to use protocol v2, on an underlying
>> + * communication mechanism that does not support v2.
>> + */
>> + dev_err_once(ec_dev->dev,
>> + "missing EC transfer API, cannot send command\n");
>> + return -EIO;
>> + }
>> +
>> ret = (*xfer_fxn)(ec_dev, msg);
>> if (msg->result == EC_RES_IN_PROGRESS) {
>> int i;
>> --
>> 2.21.0.392.gf8f6787159e-goog
>>
I'll add the patch to the for-next branch in chrome-platform repository for
auto-builders to play with. If all goes well I'll queue the patch for
chrome-platform-5.2.
Thanks,
Enric
