Messages in this thread | | | From | Guenter Roeck <> | Date | Thu, 14 Jul 2022 07:29:45 -0700 | Subject | Re: [RESEND PATCH 05/11] platform/chrome: cros_ec_proto: separate cros_ec_wait_until_complete() |
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On Wed, Jul 13, 2022 at 8:33 PM Tzung-Bi Shih <tzungbi@kernel.org> wrote: > > On Wed, Jul 13, 2022 at 11:15:47AM -0700, Guenter Roeck wrote: > > On Mon, Jun 27, 2022 at 7:49 PM Tzung-Bi Shih <tzungbi@kernel.org> wrote: > > > -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. > > Ack. > > > > + 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. > > Nack, the function has no goto labels. `return ret` follows the loop > immediately. The `break` here doesn't make it to become too complicated. > I would prefer to keep it.
Sorry, you lost me here. The code after the loop does
kfree(msg); return ret;
If kfree() is no longer necessary, only the return statement is left. So break; is identical to return ret;. Am I missing something ?
> > > > + > > > + *result = msg->result; > > > + if (msg->result != EC_RES_SUCCESS) > > > + break; > > > > Again, this can return immediately if the command buffer is on the stack. > > Nack. See above. > > > > - kfree(status_msg); > > > + if (!(status->flags & EC_COMMS_STATUS_PROCESSING)) > > > + break; > > > > Can return immediately. > > Nack. See above. >
Really, for those I think that return 0; would be better and more explicit.
> > > + kfree(msg); > > > + return ret; > > > > What should this return on timeout ? > > It returns either: > * -EAGAIN, if cros_ec_xfer_command() returned -EAGAIN > * 0, if EC_COMMS_STATUS_PROCESSING flag was on > for EC_COMMAND_RETRIES times so far. > > This is a "move" refactor. I would prefer to keep it as is and change the > behavior in later patch.
Ok.
Thanks, Guenter
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