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authorSimon Glass <sjg@chromium.org>2016-08-27 15:03:02 -0600
committerPatrick Georgi <pgeorgi@google.com>2016-10-06 21:49:25 +0200
commitaa58a9eebfc1a60ccc614ef6a064cf0ffce1c114 (patch)
tree3628144a13f7417f41db38087428bb7079944571 /src/drivers/spi
parentdd42db63489d2a2021f40aec894b1eded62e9a04 (diff)
downloadcoreboot-aa58a9eebfc1a60ccc614ef6a064cf0ffce1c114.tar.xz
spi: Add a way to show SPI transfer speed for reads
SPI read speed directly impacts boot time and we do quite a lot of reading. Add a way to easily find out the speed of SPI flash reads within coreboot. Write speed is less important since there are very few writes and they are small. BUG=chrome-os-partner:56556 BRANCH=none TEST=run on gru with SPI_SPEED_DEBUG set to 1. See the output messages: read SPI 627d4 7d73: 18455 us, 1740 KB/s, 13.920 Mbps Change-Id: Id3814bd2b7bd045cdfcc67eb1fabc861bf9ed3b2 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 82cb93f6be47efce3b0a3843bab89d2381baef89 Original-Change-Id: Iec66f5b8e3ad62f14d836a538dc7801e4ca669e7 Original-Signed-off-by: Simon Glass <sjg@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/376944 Original-Commit-Ready: Julius Werner <jwerner@chromium.org> Original-Tested-by: Simon Glass <sjg@google.com> Original-Reviewed-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://review.coreboot.org/16701 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth <martinroth@google.com>
Diffstat (limited to 'src/drivers/spi')
-rw-r--r--src/drivers/spi/cbfs_spi.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/src/drivers/spi/cbfs_spi.c b/src/drivers/spi/cbfs_spi.c
index 1895b9df1e..46e7346379 100644
--- a/src/drivers/spi/cbfs_spi.c
+++ b/src/drivers/spi/cbfs_spi.c
@@ -23,14 +23,44 @@
#include <spi_flash.h>
#include <symbols.h>
#include <cbmem.h>
+#include <timer.h>
static struct spi_flash *spi_flash_info;
+/*
+ * Set this to 1 to debug SPI speed, 0 to disable it
+ * The format is:
+ *
+ * read SPI 62854 7db7: 10416 us, 3089 KB/s, 24.712 Mbps
+ *
+ * The important number is the last one. It should roughly match your SPI
+ * clock. If it doesn't, your driver might need a little tuning.
+ */
+#define SPI_SPEED_DEBUG 0
+
static ssize_t spi_readat(const struct region_device *rd, void *b,
size_t offset, size_t size)
{
+ struct stopwatch sw;
+ bool show = SPI_SPEED_DEBUG && size >= 4 * KiB;
+
+ if (show)
+ stopwatch_init(&sw);
if (spi_flash_info->read(spi_flash_info, offset, size, b))
return -1;
+ if (show) {
+ long usecs;
+
+ usecs = stopwatch_duration_usecs(&sw);
+ u64 speed; /* KiB/s */
+ int bps; /* Bits per second */
+
+ speed = (u64)size * 1000 / usecs;
+ bps = speed * 8;
+
+ printk(BIOS_DEBUG, "read SPI %#zx %#zx: %ld us, %lld KB/s, %d.%03d Mbps\n",
+ offset, size, usecs, speed, bps / 1000, bps % 1000);
+ }
return size;
}