From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932103AbdASTiw (ORCPT ); Thu, 19 Jan 2017 14:38:52 -0500 Received: from thoth.sbs.de ([192.35.17.2]:43538 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751689AbdASTiu (ORCPT ); Thu, 19 Jan 2017 14:38:50 -0500 Subject: [PATCH v3 2/3] spi: pxa2xx: Prepare for edge-triggered interrupts To: Mark Brown References: <7b15a0910a3ad861fd32161c72559bafa7b71e29.1484592296.git.jan.kiszka@siemens.com> <87ziiqdstr.fsf@belgarion.home> <4d97e416-4d32-3b9f-0695-de116a4b26bd@siemens.com> <87r340eq28.fsf@belgarion.home> <20170118124645.6ugjwbfeq5vsh2to@sirena.org.uk> <7e5fb21d-35bd-6ac3-9e6f-cffed656997f@siemens.com> Cc: Robert Jarzmik , linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Daniel Mack , Haojian Zhuang , linux-kernel@vger.kernel.org, Andy Shevchenko , Mika Westerberg , Jarkko Nikula , Sascha Weisenberger From: Jan Kiszka Message-ID: Date: Thu, 19 Jan 2017 20:37:40 +0100 User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 In-Reply-To: <7e5fb21d-35bd-6ac3-9e6f-cffed656997f@siemens.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="MGgmsnHF44KlqhMKGCaEhePwqsahqAVSH" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --MGgmsnHF44KlqhMKGCaEhePwqsahqAVSH Content-Type: multipart/mixed; boundary="moGk529TTXn4CMRnGsuCv5BeaFVxSas4O"; protected-headers="v1" From: Jan Kiszka To: Mark Brown Cc: Robert Jarzmik , linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Daniel Mack , Haojian Zhuang , linux-kernel@vger.kernel.org, Andy Shevchenko , Mika Westerberg , Jarkko Nikula , Sascha Weisenberger Message-ID: Subject: [PATCH v3 2/3] spi: pxa2xx: Prepare for edge-triggered interrupts References: <7b15a0910a3ad861fd32161c72559bafa7b71e29.1484592296.git.jan.kiszka@siemens.com> <87ziiqdstr.fsf@belgarion.home> <4d97e416-4d32-3b9f-0695-de116a4b26bd@siemens.com> <87r340eq28.fsf@belgarion.home> <20170118124645.6ugjwbfeq5vsh2to@sirena.org.uk> <7e5fb21d-35bd-6ac3-9e6f-cffed656997f@siemens.com> In-Reply-To: <7e5fb21d-35bd-6ac3-9e6f-cffed656997f@siemens.com> --moGk529TTXn4CMRnGsuCv5BeaFVxSas4O Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable When using the a device with edge-triggered interrupts, such as MSIs, the interrupt handler has to ensure that there is a point in time during its execution where all interrupts sources are silent so that a new event can trigger a new interrupt again. This is achieved here by disabling all interrupt sources for a moment before processing them according to the status register. If a new interrupt should have arrived after we read the status, it will now re-trigger the interrupt, even in edge mode. Signed-off-by: Jan Kiszka --- Successfully tested by now. Changes to v2: - avoid inner looping by making the hardware retrigger on "forgotten" IRQ sources drivers/spi/spi-pxa2xx.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 0d10090..f9c2329 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -785,6 +785,9 @@ static irqreturn_t ssp_int(int irq, void *dev_id) if (!(status & mask)) return IRQ_NONE; =20 + pxa2xx_spi_write(drv_data, SSCR1, sccr1_reg & ~drv_data->int_cr1); + pxa2xx_spi_write(drv_data, SSCR1, sccr1_reg); + if (!drv_data->master->cur_msg) { handle_bad_msg(drv_data); /* Never fail */ --=20 2.1.4 --moGk529TTXn4CMRnGsuCv5BeaFVxSas4O-- --MGgmsnHF44KlqhMKGCaEhePwqsahqAVSH Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEARECAAYFAliBFYUACgkQitSsb3rl5xQ45wCgssrJ83vvNz5I08hR3Qo98TWa EM8AoO+7gM0G+htHEpHCNmsvlRLKhZZR =XO/8 -----END PGP SIGNATURE----- --MGgmsnHF44KlqhMKGCaEhePwqsahqAVSH--