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-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;
}