Re: [PATCH v3] platform/chrome: Use proper protocol transfer function

From: Jon Hunter
Date: Tue Sep 19 2017 - 09:45:13 EST


Hi Brian,

On 08/09/17 21:50, Brian Norris wrote:
> From: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>
>
> pkt_xfer should be used for protocol v3, and cmd_xfer otherwise. We had
> one instance of these functions correct, but not the second, fall-back
> case. We use the fall-back only when the first command returns an
> IN_PROGRESS status, which is only used on some EC firmwares where we
> don't want to constantly poll the bus, but instead back off and
> sleep/retry for a little while.
>
> Fixes: 2c7589af3c4d ("mfd: cros_ec: add proto v3 skeleton")
> Signed-off-by: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>
> Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
> Reviewed-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx>
> ---
> v3:
> * Added Javier's reviewed tag
> * It's been > 8 months since [1], so why not? And hey, Benson's officially in
> MAINTAINERS now! Too bad no one told me.
>
> [1] https://patchwork.kernel.org/patch/9450633/
>
>
> v2:
> * Add Benson in 'To:'
> * make subject prefix more obvious
>
> drivers/platform/chrome/cros_ec_proto.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 8dfa7fcb1248..e7bbdf947bbc 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -60,12 +60,14 @@ static int send_command(struct cros_ec_device *ec_dev,
> struct cros_ec_command *msg)
> {
> int ret;
> + int (*xfer_fxn)(struct cros_ec_device *ec, struct cros_ec_command *msg);
>
> if (ec_dev->proto_version > 2)
> - ret = ec_dev->pkt_xfer(ec_dev, msg);
> + xfer_fxn = ec_dev->pkt_xfer;
> else
> - ret = ec_dev->cmd_xfer(ec_dev, msg);
> + xfer_fxn = ec_dev->cmd_xfer;
>
> + ret = (*xfer_fxn)(ec_dev, msg);
> if (msg->result == EC_RES_IN_PROGRESS) {
> int i;
> struct cros_ec_command *status_msg;
> @@ -88,7 +90,7 @@ static int send_command(struct cros_ec_device *ec_dev,
> for (i = 0; i < EC_COMMAND_RETRIES; i++) {
> usleep_range(10000, 11000);
>
> - ret = ec_dev->cmd_xfer(ec_dev, status_msg);
> + ret = (*xfer_fxn)(ec_dev, status_msg);
> if (ret < 0)
> break;
>

Tegra124 Nyan-Big is currently crashing during boot with -next [0] and
bisect is pointing to this commit. Reverting the above on top of -next
does allow the board to boot successfully. Looks like this board is
proto_version 3 but I have not looked into this any further. Let me know
if you have any thoughts.

Cheers
Jon

[0]
https://nvtb.github.io//linux-next/test_next-20170919/20170918213034/boot/tegra124-nyan-big/tegra124-nyan-big/tegra_defconfig_log.txt


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