From patchwork Sat Nov 4 11:17:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 740978 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 2156EC4167D for ; Sat, 4 Nov 2023 11:18:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231879AbjKDLSs (ORCPT ); Sat, 4 Nov 2023 07:18:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232003AbjKDLSr (ORCPT ); Sat, 4 Nov 2023 07:18:47 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54A15D44 for ; Sat, 4 Nov 2023 04:17:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1699096676; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MsMY4/LcSNi8MII/naoQFzzgpbXIG9j67akh3eZNrek=; b=i0zaPa8q0U9lqZ4OoYZSfaDzrKbJ39+0cYVECd74xOwq7CZRz07+Qfs5wwJ/frP/nzIg8G Ps8Y7KBnsoicCOvQI0AE843Mlq/+9GgUW79PYlKPQEdIM/0P1jTPVrnlgNjKUnxDfrFqC3 3r/3rK2+MLFicbsYDcW+XHvO724UQ74= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-632-gz7WdBh_P0aK39uEk8irLw-1; Sat, 04 Nov 2023 07:17:54 -0400 X-MC-Unique: gz7WdBh_P0aK39uEk8irLw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id AE3B080F92B; Sat, 4 Nov 2023 11:17:53 +0000 (UTC) Received: from shalem.redhat.com (unknown [10.39.192.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0CFA3502E; Sat, 4 Nov 2023 11:17:51 +0000 (UTC) From: Hans de Goede To: Jiri Kosina , Benjamin Tissoires Cc: Hans de Goede , Douglas Anderson , Julian Sax , ahormann@gmx.net, Bruno Jesus , Dietrich , kloxdami@yahoo.com, Tim Aldridge , Rene Wagner , Federico Ricchiuto , linux-input@vger.kernel.org Subject: [PATCH 4/7] HID: i2c-hid: Move i2c_hid_finish_hwreset() to after reading the report-descriptor Date: Sat, 4 Nov 2023 12:17:40 +0100 Message-ID: <20231104111743.14668-5-hdegoede@redhat.com> In-Reply-To: <20231104111743.14668-1-hdegoede@redhat.com> References: <20231104111743.14668-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org A recent bug made me look at Microsoft's i2c-hid docs again and I noticed the following: """ 4. Issue a RESET (Host Initiated Reset) to the Device. 5. Retrieve report descriptor from the device. Note: Steps 4 and 5 may be done in parallel to optimize for time on I²C. Since report descriptors are (a) static and (b) quite long, Windows 8 may issue a request for 5 while it is waiting for a response from the device on 4. """ Which made me think that maybe on some touchpads the reset ack is delayed till after the report descriptor is read ? Testing a T-BAO Tbook Air 12.5 with a 0911:5288 (SIPODEV SP1064?) touchpad, for which the I2C_HID_QUIRK_NO_IRQ_AFTER_RESET quirk was first introduced, shows that about 1 ms after the report descriptor read finishes the reset indeed does get acked. Move the waiting for the ack to after reading the report-descriptor, so that the I2C_HID_QUIRK_NO_IRQ_AFTER_RESET quirk is no longer necessary (on this model). While at it drop the dbg_hid() for a malloc failure, malloc failures already get logged extensively by malloc itself. Link: https://bugzilla.redhat.com/show_bug.cgi?id=2247751 Signed-off-by: Hans de Goede --- drivers/hid/i2c-hid/i2c-hid-core.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c index f029ddce4766..3bd0c3d77d99 100644 --- a/drivers/hid/i2c-hid/i2c-hid-core.c +++ b/drivers/hid/i2c-hid/i2c-hid-core.c @@ -502,6 +502,12 @@ static int i2c_hid_finish_hwreset(struct i2c_hid *ihid) return ret; } +static void i2c_hid_abort_hwreset(struct i2c_hid *ihid) +{ + clear_bit(I2C_HID_RESET_PENDING, &ihid->flags); + mutex_unlock(&ihid->reset_lock); +} + static void i2c_hid_get_input(struct i2c_hid *ihid) { u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength); @@ -746,8 +752,6 @@ static int i2c_hid_parse(struct hid_device *hid) do { ret = i2c_hid_start_hwreset(ihid); - if (ret == 0) - ret = i2c_hid_finish_hwreset(ihid); if (ret) msleep(1000); } while (tries-- > 0 && ret); @@ -763,9 +767,8 @@ static int i2c_hid_parse(struct hid_device *hid) i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); } else { rdesc = kzalloc(rsize, GFP_KERNEL); - if (!rdesc) { - dbg_hid("couldn't allocate rdesc memory\n"); + i2c_hid_abort_hwreset(ihid); return -ENOMEM; } @@ -776,10 +779,21 @@ static int i2c_hid_parse(struct hid_device *hid) rdesc, rsize); if (ret) { hid_err(hid, "reading report descriptor failed\n"); + i2c_hid_abort_hwreset(ihid); goto out; } } + /* + * Windows directly reads the report-descriptor after sending reset + * and then waits for resets completion afterwards. Some touchpads + * actually wait for the report-descriptor to be read before signalling + * reset completion. + */ + ret = i2c_hid_finish_hwreset(ihid); + if (ret) + goto out; + i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); ret = hid_parse_report(hid, rdesc, rsize);