[PATCH 1/2] i2c: designware: report short transfers
From: Russell King <hidden>
Date: 2016-11-18 19:40:04
Also in:
linux-i2c
Subsystem:
i2c subsystem, i2c subsystem host drivers, synopsys designware i2c driver, the rest · Maintainers:
Andi Shyti, Mika Westerberg, Linus Torvalds
Rather than reporting success for a short transfer due to interrupt latency, report an error both to the caller, as well as to the kernel log. Signed-off-by: Russell King <redacted> --- drivers/i2c/busses/i2c-designware-core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 9703fe392543..c53058d6139c 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c@@ -758,7 +758,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) } /* no error */ - if (likely(!dev->cmd_err)) { + if (likely(!dev->cmd_err && !dev->status)) { ret = num; goto done; }
@@ -768,6 +768,11 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) ret = i2c_dw_handle_tx_abort(dev); goto done; } + + if (dev->status) + dev_err(dev->dev, + "transfer terminated early - interrupt latency too high?\n"); + ret = -EIO; done:
--
2.7.4