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Commit a804644a authored by Mike Ditto's avatar Mike Ditto Committed by Ben Dooks
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i2c-cpm: Detect and report NAK right away instead of timing out 



Make the driver report an ENXIO error immediately upon NAK instead of
waiting for another interrupt and getting a timeout.

When reading from a device that is not present or declines to respond
to, e.g., a non-existent register address, CPM immediately reports a
NAK condition in the TxBD, but the driver kept waiting until a timeout,
which takes 1 second and causes an ugly console error message.

Signed-off-by: default avatarMike Ditto <mditto@consentry.com>
Acked-by: default avatarJochen Friedrich <jochen@scram.de>
[ben-linux@fluff.org: reordered description text]
Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent 1bda7128

drivers/i2c/busses/i2c-cpm.c

+1 −0
Original line number Diff line number Diff line
@@ -365,6 +365,7 @@ static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 
		pmsg = &msgs[tptr];

		if (pmsg->flags & I2C_M_RD)

			ret = wait_event_interruptible_timeout(cpm->i2c_wait,

				(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||

				!(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),

				1 * HZ);

		else