From nobody Sat Jan 3 04:21:46 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D953E92FC0 for ; Thu, 5 Oct 2023 20:56:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231799AbjJEU4S (ORCPT ); Thu, 5 Oct 2023 16:56:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230480AbjJEU4K (ORCPT ); Thu, 5 Oct 2023 16:56:10 -0400 Received: from hosting.gsystem.sk (hosting.gsystem.sk [212.5.213.30]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id ED619B6; Thu, 5 Oct 2023 13:56:07 -0700 (PDT) Received: from gsql.ggedos.sk (off-20.infotel.telecom.sk [212.5.213.20]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by hosting.gsystem.sk (Postfix) with ESMTPSA id DE9977A062F; Thu, 5 Oct 2023 22:56:06 +0200 (CEST) From: Ondrej Zary To: Damien Le Moal , Sudip Mukherjee Cc: Christoph Hellwig , Sergey Shtylyov , Tim Waugh , linux-parport@lists.infradead.org, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/4] ata: pata_parport: add custom version of wait_after_reset Date: Thu, 5 Oct 2023 22:55:58 +0200 Message-Id: <20231005205559.6504-4-linux@zary.sk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20231005205559.6504-1-linux@zary.sk> References: <20231005205559.6504-1-linux@zary.sk> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Some parallel adapters (e.g. EXP Computer MC-1285B EPP Cable) return bogus values when there's no master device present. This can cause reset to fail, preventing the lone slave device (such as EXP Computer CD-865) from working. Add custom version of wait_after_reset that ignores master failure when a slave device is present. The custom version is also needed because the generic ata_sff_wait_after_reset uses direct port I/O for slave device detection. Signed-off-by: Ondrej Zary Reviewed-by: Sergey Shtylyov --- drivers/ata/pata_parport/pata_parport.c | 68 ++++++++++++++++++++++++- 1 file changed, 67 insertions(+), 1 deletion(-) diff --git a/drivers/ata/pata_parport/pata_parport.c b/drivers/ata/pata_par= port/pata_parport.c index cf87bbb52f1f..a7adfdcb5e27 100644 --- a/drivers/ata/pata_parport/pata_parport.c +++ b/drivers/ata/pata_parport/pata_parport.c @@ -80,6 +80,72 @@ static bool pata_parport_devchk(struct ata_port *ap, uns= igned int device) return (nsect =3D=3D 0x55) && (lbal =3D=3D 0xaa); } =20 +static int pata_parport_wait_after_reset(struct ata_link *link, + unsigned int devmask, + unsigned long deadline) +{ + struct ata_port *ap =3D link->ap; + struct pi_adapter *pi =3D ap->host->private_data; + unsigned int dev0 =3D devmask & (1 << 0); + unsigned int dev1 =3D devmask & (1 << 1); + int rc, ret =3D 0; + + ata_msleep(ap, ATA_WAIT_AFTER_RESET); + + /* always check readiness of the master device */ + rc =3D ata_sff_wait_ready(link, deadline); + if (rc) { + /* + * some adapters return bogus values if master device is not + * present, so don't abort now if a slave device is present + */ + if (!dev1) + return rc; + ret =3D -ENODEV; + } + + /* + * if device 1 was found in ata_devchk, wait for register + * access briefly, then wait for BSY to clear. + */ + if (dev1) { + int i; + + pata_parport_dev_select(ap, 1); + + /* + * Wait for register access. Some ATAPI devices fail + * to set nsect/lbal after reset, so don't waste too + * much time on it. We're gonna wait for !BSY anyway. + */ + for (i =3D 0; i < 2; i++) { + u8 nsect, lbal; + + nsect =3D pi->proto->read_regr(pi, 0, ATA_REG_NSECT); + lbal =3D pi->proto->read_regr(pi, 0, ATA_REG_LBAL); + if (nsect =3D=3D 1 && lbal =3D=3D 1) + break; + /* give drive a breather */ + ata_msleep(ap, 50); + } + + rc =3D ata_sff_wait_ready(link, deadline); + if (rc) { + if (rc !=3D -ENODEV) + return rc; + ret =3D rc; + } + } + + pata_parport_dev_select(ap, 0); + if (dev1) + pata_parport_dev_select(ap, 1); + if (dev0) + pata_parport_dev_select(ap, 0); + + return ret; +} + static int pata_parport_bus_softreset(struct ata_port *ap, unsigned int de= vmask, unsigned long deadline) { @@ -94,7 +160,7 @@ static int pata_parport_bus_softreset(struct ata_port *a= p, unsigned int devmask, ap->last_ctl =3D ap->ctl; =20 /* wait the port to become ready */ - return ata_sff_wait_after_reset(&ap->link, devmask, deadline); + return pata_parport_wait_after_reset(&ap->link, devmask, deadline); } =20 static int pata_parport_softreset(struct ata_link *link, unsigned int *cla= sses, --=20 Ondrej Zary