Hi Wolfgang,
On Sat, Mar 10, 2012 at 12:19 AM, Wolfgang Denk wd@denx.de wrote:
Dear Simon Glass,
In message 1331325178-14634-1-git-send-email-sjg@chromium.org you wrote:
Sometimes we want to be sure that the output FIFO has fully drained (e.g. because we are about to reset or the port or reset the board). Add a
Seems there is one unintentional "or".
Yes, will fix.
function for this.
Signed-off-by: Simon Glass sjg@chromium.org
Changes in v2:
- Add function to drain the ns16550's FIFO
drivers/serial/ns16550.c | 11 +++++++++++ include/ns16550.h | 3 +++ 2 files changed, 14 insertions(+), 0 deletions(-)
I dislike this. This is mostly dead code, enabled for eveybody where it just increases the memory footprint for no use.
Also I do not understand why it would be needed at all. We did not have such a requirement for any system before, so I feel you must be doing something wrong, or at least very exotic.
I put a fully explanation in the previous patch. Let me just add here that I see a 100ms delay in the reset code to allow serial output to flush, so there is at least in practice a need for this sort of thing. For most archs the extra code will be removed by the linker.
You may also recall a discussion about a platform where the SPI flash and console uart were muxed, and we had to flush the console uart before switching to SPI. I feel that draining the FIFO could/should be a useful function.
Regards, Simon
Best regards,
Wolfgang Denk
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