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author | Ben Gardner <gardner.ben@gmail.com> | 2016-03-23 09:40:37 -0500 |
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committer | Martin Roth <martinroth@google.com> | 2016-03-25 18:24:49 +0100 |
commit | 77e351d9d17cf8e8ad1c70200192ac59285b3096 (patch) | |
tree | 8d40294b9afd89dc0e71d34f5c24e30869635bb9 /util/intelmetool/me.c | |
parent | 5aecd0e533fe8e7dd5fee0a3c10ee8aabe6c8803 (diff) | |
download | coreboot-77e351d9d17cf8e8ad1c70200192ac59285b3096.tar.xz |
intel/fsp_baytrail: Fix I2C abort logic
A call to i2c_read() for a non-existent address followed by an i2c_read()
to a valid address results in a false abort status for the 2nd call.
i2c_read(1, 0x40, 0, buf, sizeof(buf)) => 0x2000000 (I2C_ERR_TIMEOUT)
i2c_read(1, 0x74, 0, buf, sizeof(buf)) => 0x4000000 (I2C_ERR_ABORT)
Because the abort status register is cleared on read and wait_tx_fifo()
reads it twice, the returned status does not contain the abort status.
Fixing that changed the 2nd read to reflect the abort status.
i2c_read(1, 0x40, 0, buf, sizeof(buf)) => 0x2000000 (I2C_ERR_TIMEOUT)
i2c_read(1, 0x74, 0, buf, sizeof(buf)) => 0x4000001 (I2C_ERR_ABORT)
Bit 0 indicates that the address was not acknowledged by any slave.
That's the abort status from the previous transaction.
So I added a read of the abort status before starting a transaction in
both i2c_read() and i2c_write().
i2c_read(1, 0x40, 0, buf, sizeof(buf)) => 0x2000000 (I2C_ERR_TIMEOUT)
i2c_read(1, 0x74, 0, buf, sizeof(buf)) => 0 (I2C_SUCCESS)
Tested on a Bay Trail E3845 SoC.
Change-Id: I39e4ff4206587267b6fceef58f4a567bf162fbbe
Signed-off-by: Ben Gardner <gardner.ben@gmail.com>
Reviewed-on: https://review.coreboot.org/14160
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Diffstat (limited to 'util/intelmetool/me.c')
0 files changed, 0 insertions, 0 deletions