Hi Wolfgang,
On Sat, Oct 15, 2011 at 12:08 PM, Wolfgang Denk wd@denx.de wrote:
Dear Simon Glass,
In message 1318694632-21872-1-git-send-email-sjg@chromium.org you wrote:
From: Scott Wood scottwood@freescale.com
From: Scott Wood scottwood@freescale.com
This improves the performance of U-Boot when accepting rapid input, such as pasting a sequence of commands.
Without this patch, on P4080DS I see a maximum of around 5 lines can be pasted. With this patch, it handles around 70 lines before lossage, long enough for most things you'd paste.
With it enabled, on ppc it's an extra 396 bytes of image size, and 1056 bytes of BSS.
ARM note from Simon Glass sjg@chromium.org - ARM code size goes from 212 to 484 bytes (extra 272 bytes), BSS to 1056 bytes.
Signed-off-by: Scott Wood scottwood@freescale.com
Changes in v2:
- Fix checkpatch warnings, the other one was already there
Changes in v3:
- Use CONFIG_NS16550_BUFFER_READS to set the buffer size also
README | 12 ++++++ drivers/serial/ns16550.c | 96 +++++++++++++++++++++++++++++++++++++++++++-- drivers/serial/serial.c | 5 +- include/ns16550.h | 4 +- 4 files changed, 108 insertions(+), 9 deletions(-)
diff --git a/README b/README index 7e032a9..1150d6c 100644 --- a/README +++ b/README @@ -2862,6 +2862,18 @@ use the "saveenv" command to store a valid environment. space for already greatly restricted images, including but not limited to NAND_SPL configurations.
+- CONFIG_NS16550_BUFFER_READS:
- Instead of reading directly from the receive register
- every time U-Boot is ready for another byte, keep a
- buffer and fill it from the hardware fifo every time
- U-Boot reads a character. This helps U-Boot keep up with
- a larger amount of rapid input, such as happens when
- pasting text into the terminal.
- To use this option, define CONFIG_NS16550_BUFFER_READS to
- the size of the buffer you want (256 is a reasonable value).
If we should accept that patch, then please chose a better name here. For example, CONFIG_NS16550_RBUF_SIZE (or similar) seems to be a somewhat better choice.
Yes much better.
+#ifdef CONFIG_NS16550_BUFFER_READS
+#define BUF_SIZE CONFIG_NS16550_BUFFER_READS +#define NUM_PORTS 4
+struct ns16550_priv {
- char buf[BUF_SIZE];
- unsigned int head, tail;
+};
There is little sense in adding another variable here. Just write:
char buf[CONFIG_NS16550_BUFFER_READS];
(or whatever variable name would be used here).
Yes, this makes more sense with the new name, too.
Regards, Simon
Best regards,
Wolfgang Denk
-- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de "The release of emotion is what keeps us health. Emotionally healthy." "That may be, Doctor. However, I have noted that the healthy release of emotion is frequently unhealthy for those closest to you." -- McCoy and Spock, "Plato's Stepchildren", stardate 5784.3