[U-Boot] [[PATCH V2 1/1] console: Improve TFTP booting performance

[Wolfgang Denk]

Dear Jim Lin,

In message <1363861408-21042-1-git-send-email-jilin at nvidia.com> you wrote:
> TFTP booting is observed a little bit slow, especially when a USB
> keyboard is installed.
> The fix is to check whether Ctrl-C key is pressed every
> CONFIG_CTRLC_POLL_S second.
> 
> Signed-off-by: Jim Lin <jilin at nvidia.com>
> ---
> Changes in V2:
>  1. Change configuration name from CONFIG_CTRLC_POLL_MS to CONFIG_CTRLC_POLL_S.
>  2. New code will be executed only when CONFIG_CTRLC_POLL_S is defined in
>     configuration header file.
>  3. Add description in README.console.
> 
>  common/console.c   |   16 ++++++++++++++++
>  doc/README.console |   10 ++++++++++
>  2 files changed, 26 insertions(+), 0 deletions(-)

NAK.

You modify not only the TFTP related code, but the general behaviour
everywhere.  For you, and for TFTP operation, it might be sufficient
to check for ^C only every few seconds, but in general this is not the
case.

You write your problem comes from using a USB keyboard, where tstc()
appears to be a slow operation.

In this case it would be best to fix the problem at the root, i. e.
improve the performance of tstc() so it doesn't hurt any more.

What you are doing here is just paperingover a problem which may (and
will) hit you in other places as well.  Do not do that.  Fix the root
problem.

Best regards,

Wolfgang Denk

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