From a804644a1a31a0b85e4c7d3c49f30419513cb6c1 Mon Sep 17 00:00:00 2001 From: Mike Ditto <mditto@consentry.com> Date: Tue, 16 Dec 2008 20:17:09 +0000 Subject: [PATCH] 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: Mike Ditto <mditto@consentry.com> Acked-by: Jochen Friedrich <jochen@scram.de> [ben-linux@fluff.org: reordered description text] Signed-off-by: Ben Dooks <ben-linux@fluff.org> --- drivers/i2c/busses/i2c-cpm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index 228f757230639..3fcf78e906db1 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -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 -- GitLab