[U-Boot] [RFC PATCH v2 11/20] fastboot: net: Change 'continue' so it matches USB fastboot

[Joe Hershberger]

On Tue, May 8, 2018 at 4:20 AM, Alex Kiernan <alex.kiernan at gmail.com> wrote:
> On Thu, May 3, 2018 at 9:58 PM Joe Hershberger <joe.hershberger at ni.com>
> wrote:
>
>> On Mon, Apr 30, 2018 at 3:32 AM, Alex Kiernan <alex.kiernan at gmail.com>
> wrote:
>> > Change the behaviour of 'continue' so that we simply exit the fastboot
>> > server and leave the caller to decide what to do next. This matches
>> > the USB fastboot behaviour.
>
>> Good, I was considering recommending this approach.
>
>> Acked-by: Joe Hershberger <joe.hershberger at ni.com>
>
>> >
>> > Signed-off-by: Alex Kiernan <alex.kiernan at gmail.com>
>> > ---
>> >
>> > Changes in v2: None
>> >
>> >  net/fastboot.c | 13 +++----------
>> >  1 file changed, 3 insertions(+), 10 deletions(-)
>> >
>> > diff --git a/net/fastboot.c b/net/fastboot.c
>> > index cd09ada..ed13890 100644
>> > --- a/net/fastboot.c
>> > +++ b/net/fastboot.c
>> > @@ -218,8 +218,6 @@ static void fastboot_send(struct fastboot_header
> fb_header, char *fastboot_data,
>> >         if (!strncmp("OKAY", response, 4)) {
>> >                 if (!strcmp("boot", cmd_string)) {
>> >                         boot_downloaded_image();
>> > -               } else if (!strcmp("continue", cmd_string)) {
>> > -                       run_command(env_get("bootcmd"), CMD_FLAG_ENV);
>> >                 } else if (!strncmp("reboot", cmd_string, 6)) {
>> >                         /* Matches reboot or reboot-bootloader */
>> >                         do_reset(NULL, 0, 0, NULL);
>> > @@ -313,20 +311,15 @@ static void fb_erase(char *response)
>> >  #endif
>> >
>> >  /**
>> > - * Continues normal boot process by running "bootcmd". Writes
>> > + * Continues normal boot process by exiting fastboot server. Writes
>> >   * to response.
>> >   *
>> >   * @param repsonse    Pointer to fastboot response buffer
>> >   */
>> >  static void fb_continue(char *response)
>> >  {
>> > -       char *bootcmd;
>> > -
>> > -       bootcmd = env_get("bootcmd");
>> > -       if (bootcmd)
>> > -               fastboot_okay(NULL, response);
>> > -       else
>> > -               fastboot_fail("bootcmd not set", response);
>> > +       net_set_state(NETLOOP_SUCCESS);
>> > +       fastboot_okay(NULL, response);
>> >  }
>> >
>
> I'm struggling with this returning the final ACK to the client correctly.
> If I add something like mdelay(5) before exiting the server, then I get the
> final ACK, without that, I never see it hit the network, even though I can
> see it traversing all the layers of the net code if I wind up the debug
> (and of course it makes it out if I wind up the debug, presumably as it
> then goes much slower).
>
> Wild hand wavey speculation... it's getting lost in something like a DMA
> buffer in the network driver which gets torn down before it makes it onto
> the wire? This is using the TI CPSW on an am335x.

Sounds like a reasonable theory.

The eth driver for that board probably needs to check for the TX
channel to be in a quiescent state in the davinci_eth_close() function
before tearing it down.

-Joe