diff options
author | Hans de Goede <hdegoede@redhat.com> | 2015-05-05 13:13:36 +0200 |
---|---|---|
committer | Hans de Goede <hdegoede@redhat.com> | 2015-05-19 18:37:30 +0200 |
commit | a8552c7c9b53d1d4f36b95f2c80812d8a7bb4fff (patch) | |
tree | 72406ed8d3ee56813c595d837ec69864e0ee8df3 /common | |
parent | f9b08fbf11add614f1773c5378a9026cd3d5c75f (diff) |
console: Fix pre-console flushing via cfb_console being very slow
On my A10 OlinuxIno Lime I noticed a huge (5+ seconds) delay coming from
console_init_r. This turns out to be caused by the preconsole buffer flushing
to the cfb_console. The Lime only has a 16 bit memory bus and that is already
heavy used to scan out the 1920x1080 framebuffer.
The problem is that print_pre_console_buffer() was printing the buffer once
character at a time and the cfb_console code then ends up doing a cache-flush
for touched display lines for each character.
This commit fixes this by first building a 0 terminated buffer and then
printing it in one puts() call, avoiding unnecessary cache flushes.
This changes the time for the flush from 5+ seconds to not noticable.
The downside of this approach is that the pre-console buffer needs to fit
on the stack, this is not that much to ask since we are talking about plain
text here. This commit also adjusts the sunxi CONFIG_PRE_CON_BUF_SZ to
actually fit on the stack. Sunxi currently is the only user of the pre-console
code so no other boards need to be adjusted.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Diffstat (limited to 'common')
-rw-r--r-- | common/console.c | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/common/console.c b/common/console.c index 3f25e76fe7..00582224d4 100644 --- a/common/console.c +++ b/common/console.c @@ -200,15 +200,15 @@ static void console_putc(int file, const char c) } #ifdef CONFIG_PRE_CONSOLE_BUFFER -static void console_putc_noserial(int file, const char c) +static void console_puts_noserial(int file, const char *s) { int i; struct stdio_dev *dev; for (i = 0; i < cd_count[file]; i++) { dev = console_devices[file][i]; - if (dev->putc != NULL && strcmp(dev->name, "serial") != 0) - dev->putc(dev, c); + if (dev->puts != NULL && strcmp(dev->name, "serial") != 0) + dev->puts(dev, s); } } #endif @@ -251,10 +251,10 @@ static inline void console_putc(int file, const char c) } #ifdef CONFIG_PRE_CONSOLE_BUFFER -static inline void console_putc_noserial(int file, const char c) +static inline void console_puts_noserial(int file, const char *s) { if (strcmp(stdio_devices[file]->name, "serial") != 0) - stdio_devices[file]->putc(stdio_devices[file], c); + stdio_devices[file]->puts(stdio_devices[file], s); } #endif @@ -425,22 +425,26 @@ static void pre_console_puts(const char *s) static void print_pre_console_buffer(int flushpoint) { - unsigned long i = 0; - char *buffer = (char *)CONFIG_PRE_CON_BUF_ADDR; + unsigned long in = 0, out = 0; + char *buf_in = (char *)CONFIG_PRE_CON_BUF_ADDR; + char buf_out[CONFIG_PRE_CON_BUF_SZ + 1]; if (gd->precon_buf_idx > CONFIG_PRE_CON_BUF_SZ) - i = gd->precon_buf_idx - CONFIG_PRE_CON_BUF_SZ; + in = gd->precon_buf_idx - CONFIG_PRE_CON_BUF_SZ; - while (i < gd->precon_buf_idx) - switch (flushpoint) { - case PRE_CONSOLE_FLUSHPOINT1_SERIAL: - putc(buffer[CIRC_BUF_IDX(i++)]); - break; - case PRE_CONSOLE_FLUSHPOINT2_EVERYTHING_BUT_SERIAL: - console_putc_noserial(stdout, - buffer[CIRC_BUF_IDX(i++)]); - break; - } + while (in < gd->precon_buf_idx) + buf_out[out++] = buf_in[CIRC_BUF_IDX(in++)]; + + buf_out[out] = 0; + + switch (flushpoint) { + case PRE_CONSOLE_FLUSHPOINT1_SERIAL: + puts(buf_out); + break; + case PRE_CONSOLE_FLUSHPOINT2_EVERYTHING_BUT_SERIAL: + console_puts_noserial(stdout, buf_out); + break; + } } #else static inline void pre_console_putc(const char c) {} |