From patchwork Tue Nov 21 20:39:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: RD Babiera X-Patchwork-Id: 13463562 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="aOCGaQgV" Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C14A5D47 for ; Tue, 21 Nov 2023 12:39:58 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-5cbab2450c5so16649517b3.3 for ; Tue, 21 Nov 2023 12:39:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1700599198; x=1701203998; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=gX/jHSjVMvQMuoAzLeVpINA8vcf/XXhZAAMF7Dr1Htw=; b=aOCGaQgVUQo1071NiL6+IclGxNl0CzP6bVNYSy4hLK8RetBCFFhT472KqD5kyB05VX teqbiboqAbslRIkKRe+R67k/7raJQBzgGb+tZYP0W2v8xTpsTpHNhtBDTtcovBhdsac/ +tc2iJ1hGq6k+7iVNorThplXqANAJfJmI7a7PpUMHdeLQtqI9sm6cOhAYk9tu6JvklMT LH2n/Hc5yfyHQakYqNgMKHkxDR/z7B1Z7IBgUAsHftg8G9Pft3ESmAb4M1rjUbMgoKuS ZZYYdOKZzvx8OVAkVnnde8A/7YnKt4AuhgUKHeTU3bpTqyhyjdN08S5QsNkQqEMV2IkL 6MQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700599198; x=1701203998; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=gX/jHSjVMvQMuoAzLeVpINA8vcf/XXhZAAMF7Dr1Htw=; b=AXNAlQnRRrI5TLCoHKY9LrK1HjAO4mTQsZiTTZCkuQPRXR2EaJBoNOFSUh8DQwufh7 orevqhFLb/NXXhJftLotBkp8Qld+AGIE6jffdO89qHi4y59RoFk+BZJInprxaXEtLO0n Cx999fzB04VwChBrwiDaigT1phnOteceCIjzgQqkPBYabRo7eFxOqOgN011TFQ8RtJC3 QGpd8Wj/6Ljh5BohighiYMtjbFfRfPWQIca184qwcmZfEtn842IHdXLfe7a/996HJQOW KMQ+U487jNkHL7ghC/7ixKnsjDtoZcfiv1yppdX7ivPsF0qNSx3z8FkzhDT3rJSSb9wS kocA== X-Gm-Message-State: AOJu0YxCd7nCsMciAff1xaMgXs7PLiEA+/Zglv8BPGv7boBz/JkiQUk9 SFbkwXsZUAmUTbF8bK9LvHq6zyyAJHmQt2Y= X-Google-Smtp-Source: AGHT+IELPIuKhD/YAdrhnQZvEYt7QZu6NUG23WB70IGl5qV4jBVbzdeQNxFjRT6VdyJMnCt2MVuVZg50EBBOzjE= X-Received: from rdbabiera.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:18a8]) (user=rdbabiera job=sendgmr) by 2002:a81:4f84:0:b0:5ca:4a99:7008 with SMTP id d126-20020a814f84000000b005ca4a997008mr2821ywb.10.1700599198097; Tue, 21 Nov 2023 12:39:58 -0800 (PST) Date: Tue, 21 Nov 2023 20:39:55 +0000 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Developer-Key: i=rdbabiera@google.com; a=openpgp; fpr=639A331F1A21D691815CE090416E17CA2BBBD5C8 X-Developer-Signature: v=1; a=openpgp-sha256; l=2637; i=rdbabiera@google.com; h=from:subject; bh=g3cATdDr31eccLe03DHQgAdZzg53ANBo3tzI1LoDz8E=; b=owGbwMvMwCFW0bfok0KS4TbG02pJDKmxorMqPUL6W6ov9tm+8mlYddhft0n+7cGy60HTA+QE7 85IsPjYUcrCIMbBICumyKLrn2dw40rqljmcNcYwc1iZQIYwcHEKwETihRkZei2t3rbxzJb1zuep fqkQnLblpNvN43v2m3JyJufs+BmwnJHh796Q47Xak7i22gczPVD9yffhSs+uPzFrvBLtF3Lyzc1 iBQA= X-Mailer: git-send-email 2.43.0.rc1.413.gea7ed67945-goog Message-ID: <20231121203954.173364-2-rdbabiera@google.com> Subject: [PATCH v1] usb: typec: class: fix typec_altmode_put_partner to put plugs From: RD Babiera To: heikki.krogerus@linux.intel.com, gregkh@linuxfoundation.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, badhri@google.com, RD Babiera , stable@vger.kernel.org When releasing an Alt Mode, typec_altmode_release called by a plug device will not release the plug Alt Mode, meaning that a port will hold a reference to a plug Alt Mode even if the port partner is unregistered. As a result, typec_altmode_get_plug() can return an old plug altmode. Currently, typec_altmode_put_partner does not raise issues when unregistering a partner altmode. Looking at the current implementation: > static void typec_altmode_put_partner(struct altmode *altmode) > { > struct altmode *partner = altmode->partner; When called by the partner Alt Mode, then partner evaluates to the port's Alt Mode. When called by the plug Alt Mode, this also evaluates to the port's Alt Mode. > struct typec_altmode *adev; > > if (!partner) > return; > > adev = &partner->adev; This always evaluates to the port's typec_altmode > if (is_typec_plug(adev->dev.parent)) { > struct typec_plug *plug = to_typec_plug(adev->dev.parent); > > partner->plug[plug->index] = NULL; If the routine is called to put the plug's Alt mode and altmode refers to the plug, then adev referring to the port can never be a typec_plug. If altmode refers to the port, adev will always refer to the port partner, which runs the block below. > } else { > partner->partner = NULL; > } > put_device(&adev->dev); > } When calling typec_altmode_set_partner, a registration always calls get_device() on the port partner or the plug being registered, therefore typec_altmode_put_partner should put_device() the same device. By changing adev to altmode->adev, we make sure to put the correct device and properly unregister plugs. The reason port partners are always properly unregistered is because even when adev refers to the port, the port partner gets nullified in the else block. The port device currently gets put(). Fixes: 8a37d87d72f0 ("usb: typec: Bus type for alternate modes") Cc: stable@vger.kernel.org Signed-off-by: RD Babiera --- drivers/usb/typec/class.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) base-commit: b85ea95d086471afb4ad062012a4d73cd328fa86 diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c index 2e0451bd336e..803be1943445 100644 --- a/drivers/usb/typec/class.c +++ b/drivers/usb/typec/class.c @@ -267,7 +267,7 @@ static void typec_altmode_put_partner(struct altmode *altmode) if (!partner) return; - adev = &partner->adev; + adev = &altmode->adev; if (is_typec_plug(adev->dev.parent)) { struct typec_plug *plug = to_typec_plug(adev->dev.parent);