From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49112 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753668AbcKULlb (ORCPT ); Mon, 21 Nov 2016 06:41:31 -0500 Subject: Patch "mfd: stmpe: Fix RESET regression on STMPE2401" has been added to the 4.8-stable tree To: linus.walleij@linaro.org, amelie.delaunay@st.com, gregkh@linuxfoundation.org, lee.jones@linaro.org, patrice.chotard@st.com Cc: , From: Date: Mon, 21 Nov 2016 12:41:23 +0100 Message-ID: <147972848368209@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled mfd: stmpe: Fix RESET regression on STMPE2401 to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mfd-stmpe-fix-reset-regression-on-stmpe2401.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From f40584200bc4af7aa4399635b9ac213c62a13ae7 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 1 Nov 2016 10:22:53 +0100 Subject: mfd: stmpe: Fix RESET regression on STMPE2401 From: Linus Walleij commit f40584200bc4af7aa4399635b9ac213c62a13ae7 upstream. Since commit c4dd1ba355aae2bc3d1213da6c66c53e3c31e028 ("mfd: stmpe: Add reset support for all STMPE variant") we're resetting the STMPE expanders before use. This caused a regression on the STMP2401 on the Nomadik NHK8815: stmpe-i2c 0-0043: stmpe2401 detected, chip id: 0x101 nmk-i2c 101f8000.i2c0: write to slave 0x43 timed out nmk-i2c 101f8000.i2c0: no ack received after address transmission stmpe-i2c 0-0044: stmpe2401 detected, chip id: 0x101 nmk-i2c 101f8000.i2c0: write to slave 0x44 timed out nmk-i2c 101f8000.i2c0: no ack received after address transmission It turns out that we start to poll for the reset bit to go low again too quickly: the STMPE2401 is not yet online and ready to be asked for the status of the RESET bit. By introducing a 10ms delay before starting to hammer the register for information, we get back to normal: stmpe-i2c 0-0043: stmpe2401 detected, chip id: 0x101 stmpe-i2c 0-0044: stmpe2401 detected, chip id: 0x101 Cc: Amelie Delaunay Fixes: c4dd1ba355aa ("mfd: stmpe: Add reset support for all STMPE variant") Signed-off-by: Linus Walleij Acked-by: Patrice Chotard Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman --- drivers/mfd/stmpe.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/mfd/stmpe.c +++ b/drivers/mfd/stmpe.c @@ -761,6 +761,8 @@ static int stmpe1801_reset(struct stmpe if (ret < 0) return ret; + msleep(10); + timeout = jiffies + msecs_to_jiffies(100); while (time_before(jiffies, timeout)) { ret = __stmpe_reg_read(stmpe, STMPE1801_REG_SYS_CTRL); Patches currently in stable-queue which might be from linus.walleij@linaro.org are queue-4.8/gpio-do-not-double-check-direction-on-sleeping-chips.patch queue-4.8/mfd-stmpe-fix-reset-regression-on-stmpe2401.patch queue-4.8/i2c-mux-fix-up-dependencies.patch