From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Korsgaard Subject: Re: [PATCH] i2c: ocores: Add missing wake_up() call upon state change to STATE_DONE Date: Fri, 16 Jun 2017 14:52:34 +0200 Message-ID: <87a858hz71.fsf@dell.be.48ers.dk> References: <20170616092317.584-1-sr@denx.de> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-wm0-f67.google.com ([74.125.82.67]:36359 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753765AbdFPMwm (ORCPT ); Fri, 16 Jun 2017 08:52:42 -0400 Received: by mail-wm0-f67.google.com with SMTP id d17so4875131wme.3 for ; Fri, 16 Jun 2017 05:52:37 -0700 (PDT) In-Reply-To: <20170616092317.584-1-sr@denx.de> (Stefan Roese's message of "Fri, 16 Jun 2017 11:23:17 +0200") Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Stefan Roese Cc: linux-i2c@vger.kernel.org, Wolfram Sang >>>>> "Stefan" == Stefan Roese writes: > I've noticed that this driver adds a timeout pause of 1 second after > each xfer. This is due to the wait_event_timeout() call in ocores_xfer() > using a "HZ" timeout value and a missing call to wake_up() in > ocores_process() called by the interrupt handler when the state changes > to STATE_DONE at the end of the frame. > This patch adds the missing call resulting in the removal of this 1 > second timeout delay after each xfer. > Signed-off-by: Stefan Roese > Cc: Wolfram Sang > --- > drivers/i2c/busses/i2c-ocores.c | 1 + > 1 file changed, 1 insertion(+) > diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c > index 34f1889a4073..5f8395ea0106 100644 > --- a/drivers/i2c/busses/i2c-ocores.c > +++ b/drivers/i2c/busses/i2c-ocores.c > @@ -191,6 +191,7 @@ static void ocores_process(struct ocores_i2c *i2c) > } else { > i2c-> state = STATE_DONE; > oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); > + wake_up(&i2c->wait); > return; It is close to 10 years ago since I last had access to any boards with the ocores controller, but the logic in ocores_process() indicates that the controller would generate another interrupt once the stop condition has been sent: if ((i2c->state == STATE_DONE) || (i2c->state == STATE_ERROR)) { /* stop has been sent */ oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK); wake_up(&i2c->wait); return; } Do you not see this interrupt? -- Bye, Peter Korsgaard