Messages in this thread |  | | From | Guenter Roeck <> | Date | Wed, 13 Jul 2022 11:15:47 -0700 | Subject | Re: [RESEND PATCH 05/11] platform/chrome: cros_ec_proto: separate cros_ec_wait_until_complete() |
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On Mon, Jun 27, 2022 at 7:49 PM Tzung-Bi Shih <tzungbi@kernel.org> wrote: > > EC returns EC_RES_IN_PROGRESS if the host command needs more time to > complete. Whenever receives the return code, cros_ec_send_command() > sends EC_CMD_GET_COMMS_STATUS to query the command status. > > Separate cros_ec_wait_until_complete() from cros_ec_send_command(). > It sends EC_CMD_GET_COMMS_STATUS and waits until the previous command > was completed, or encountered error, or timed out. > > Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org> > --- > drivers/platform/chrome/cros_ec_proto.c | 75 ++++++++++++------------- > 1 file changed, 36 insertions(+), 39 deletions(-) > > diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c > index 0cec013be3d3..466ecb063bd6 100644 > --- a/drivers/platform/chrome/cros_ec_proto.c > +++ b/drivers/platform/chrome/cros_ec_proto.c > @@ -134,53 +134,50 @@ static int cros_ec_xfer_command(struct cros_ec_device *ec_dev, struct cros_ec_co > return ret; > } > > -static int cros_ec_send_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg) > +static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t *result) > { > - int ret = cros_ec_xfer_command(ec_dev, msg); > + struct cros_ec_command *msg; > + struct ec_response_get_comms_status *status; > + int ret = 0, i; > + > + msg = kzalloc(sizeof(*msg) + sizeof(*status), GFP_KERNEL); > + if (!msg) > + return -ENOMEM;
AFAICS this is always 24 bytes. I would suggest to allocate it on the stack to reduce overhead. > > - if (msg->result == EC_RES_IN_PROGRESS) { > - int i; > - struct cros_ec_command *status_msg; > - struct ec_response_get_comms_status *status; > + msg->command = EC_CMD_GET_COMMS_STATUS; > + msg->insize = sizeof(*status); > > - status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status), > - GFP_KERNEL); > - if (!status_msg) > - return -ENOMEM; > + status = (struct ec_response_get_comms_status *)msg->data; > > - status_msg->version = 0; > - status_msg->command = EC_CMD_GET_COMMS_STATUS; > - status_msg->insize = sizeof(*status); > - status_msg->outsize = 0; > + /* Query the EC's status until it's no longer busy or we encounter an error. */ > + for (i = 0; i < EC_COMMAND_RETRIES; ++i) { > + usleep_range(10000, 11000); > > - /* > - * Query the EC's status until it's no longer busy or > - * we encounter an error. > - */ > - for (i = 0; i < EC_COMMAND_RETRIES; i++) { > - usleep_range(10000, 11000); > - > - trace_cros_ec_request_start(status_msg); > - ret = (*xfer_fxn)(ec_dev, status_msg); > - trace_cros_ec_request_done(status_msg, ret); > - if (ret == -EAGAIN) > - continue; > - if (ret < 0) > - break; > - > - msg->result = status_msg->result; > - if (status_msg->result != EC_RES_SUCCESS) > - break; > - > - status = (struct ec_response_get_comms_status *) > - status_msg->data; > - if (!(status->flags & EC_COMMS_STATUS_PROCESSING)) > - break; > - } > + ret = cros_ec_xfer_command(ec_dev, msg); > + if (ret == -EAGAIN) > + continue; > + if (ret < 0) > + break;
With the command allocated on the stack, this can return immediately.
> + > + *result = msg->result; > + if (msg->result != EC_RES_SUCCESS) > + break;
Again, this can return immediately if the command buffer is on the stack.
> > - kfree(status_msg); > + if (!(status->flags & EC_COMMS_STATUS_PROCESSING)) > + break;
Can return immediately.
> } > > + kfree(msg); > + return ret;
What should this return on timeout ?
> +} > + > +static int cros_ec_send_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg) > +{ > + int ret = cros_ec_xfer_command(ec_dev, msg); > + > + if (msg->result == EC_RES_IN_PROGRESS) > + ret = cros_ec_wait_until_complete(ec_dev, &msg->result); > + > return ret; > } > > -- > 2.37.0.rc0.161.g10f37bed90-goog >
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