Messages in this thread | | | Date | Tue, 25 Feb 2020 11:55:19 -0800 | From | Prashant Malani <> | Subject | Re: [PATCH 4/8] platform/chrome: cros_ec_chardev: Use cros_ec_cmd_xfer_status helper |
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Hi Enric,
On Thu, Feb 20, 2020 at 04:58:55PM +0100, Enric Balletbo i Serra wrote: > This patch makes use of cros_ec_cmd_xfer_status() instead of > cros_ec_cmd_xfer(). In this case the change is trivial and the only > reason to do it is because we want to make cros_ec_cmd_xfer() a private > function for the EC protocol and let people only use the > cros_ec_cmd_xfer_status() to return Linux standard error codes. > > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> > --- > > drivers/platform/chrome/cros_ec_chardev.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/platform/chrome/cros_ec_chardev.c b/drivers/platform/chrome/cros_ec_chardev.c > index c65e70bc168d..b51ab24055f3 100644 > --- a/drivers/platform/chrome/cros_ec_chardev.c > +++ b/drivers/platform/chrome/cros_ec_chardev.c > @@ -301,7 +301,7 @@ static long cros_ec_chardev_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg) > } > > s_cmd->command += ec->cmd_offset; > - ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd); > + ret = cros_ec_cmd_xfer_status(ec->ec_dev, s_cmd);
One issue I see here is that if we were to later convert cros_ec_cmd_xfer_status() to cros_ec_cmd(), we would lose the s_cmd->result value, since I was hoping to avoid returning msg->result via a pointer parameter. I don't know if userspace actually uses that, but I am assuming it does.
So, should cros_ec_cmd() keep the *result pointer like so ?:
int cros_ec_cmd(struct cros_ec_device *ec, u32 version, u32 command, void *outdata, u32 outsize, void *indata, u32 insize, u32 *result);
This way, we can manually re-populate s_cmd->result with |*result|.
Or, should we drop msg->result while returning s_cmd to userspace? I am guessing the answer is no, but thought I'd check with you first.
Best regards,
> /* Only copy data to userland if data was received. */ > if (ret < 0) > goto exit; > -- > 2.25.0 >
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