From nobody Tue Feb 10 20:48:14 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1676395300698336.07786475756006; Tue, 14 Feb 2023 09:21:40 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pRyxE-0001h1-Sw; Tue, 14 Feb 2023 12:18:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pRyxC-0001et-DS; Tue, 14 Feb 2023 12:18:54 -0500 Received: from mail.ozlabs.org ([2404:9400:2221:ea00::3] helo=gandalf.ozlabs.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pRyxA-0004qb-9q; Tue, 14 Feb 2023 12:18:54 -0500 Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4PGSbs1x72z4x5Z; Wed, 15 Feb 2023 04:18:49 +1100 (AEDT) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4PGSbn1jM0z4x82; Wed, 15 Feb 2023 04:18:44 +1100 (AEDT) From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= To: qemu-arm@nongnu.org, qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, Joel Stanley , Andrew Jeffery , Markus Armbruster , Peter Maydell , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Klaus Jensen , Corey Minyard , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Subject: [PATCH 2/8] hw/i2c: only schedule pending master when bus is idle Date: Tue, 14 Feb 2023 18:18:24 +0100 Message-Id: <20230214171830.681594-3-clg@kaod.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230214171830.681594-1-clg@kaod.org> References: <20230214171830.681594-1-clg@kaod.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2404:9400:2221:ea00::3; envelope-from=SRS0=ZGUx=6K=kaod.org=clg@ozlabs.org; helo=gandalf.ozlabs.org X-Spam_score_int: -39 X-Spam_score: -4.0 X-Spam_bar: ---- X-Spam_report: (-4.0 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1676395301672100001 From: Klaus Jensen It is not given that the current master will release the bus after a transfer ends. Only schedule a pending master if the bus is idle. Fixes: 37fa5ca42623 ("hw/i2c: support multiple masters") Signed-off-by: Klaus Jensen Acked-by: Corey Minyard Message-Id: <20221116084312.35808-2-its@irrelevant.dk> Signed-off-by: C=C3=A9dric Le Goater --- include/hw/i2c/i2c.h | 2 ++ hw/i2c/aspeed_i2c.c | 2 ++ hw/i2c/core.c | 37 ++++++++++++++++++++++--------------- 3 files changed, 26 insertions(+), 15 deletions(-) diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h index 9b9581d230..2a3abacd1b 100644 --- a/include/hw/i2c/i2c.h +++ b/include/hw/i2c/i2c.h @@ -141,6 +141,8 @@ int i2c_start_send(I2CBus *bus, uint8_t address); */ int i2c_start_send_async(I2CBus *bus, uint8_t address); =20 +void i2c_schedule_pending_master(I2CBus *bus); + void i2c_end_transfer(I2CBus *bus); void i2c_nack(I2CBus *bus); void i2c_ack(I2CBus *bus); diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c index c166fd20fa..1f071a3811 100644 --- a/hw/i2c/aspeed_i2c.c +++ b/hw/i2c/aspeed_i2c.c @@ -550,6 +550,8 @@ static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus= , uint64_t value) } SHARED_ARRAY_FIELD_DP32(bus->regs, reg_cmd, M_STOP_CMD, 0); aspeed_i2c_set_state(bus, I2CD_IDLE); + + i2c_schedule_pending_master(bus->bus); } =20 if (aspeed_i2c_bus_pkt_mode_en(bus)) { diff --git a/hw/i2c/core.c b/hw/i2c/core.c index d4ba8146bf..bed594fe59 100644 --- a/hw/i2c/core.c +++ b/hw/i2c/core.c @@ -185,22 +185,39 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, = bool is_recv) =20 void i2c_bus_master(I2CBus *bus, QEMUBH *bh) { - if (i2c_bus_busy(bus)) { - I2CPendingMaster *node =3D g_new(struct I2CPendingMaster, 1); - node->bh =3D bh; + I2CPendingMaster *node =3D g_new(struct I2CPendingMaster, 1); + node->bh =3D bh; + + QSIMPLEQ_INSERT_TAIL(&bus->pending_masters, node, entry); +} + +void i2c_schedule_pending_master(I2CBus *bus) +{ + I2CPendingMaster *node; =20 - QSIMPLEQ_INSERT_TAIL(&bus->pending_masters, node, entry); + if (i2c_bus_busy(bus)) { + /* someone is already controlling the bus; wait for it to release = it */ + return; + } =20 + if (QSIMPLEQ_EMPTY(&bus->pending_masters)) { return; } =20 - bus->bh =3D bh; + node =3D QSIMPLEQ_FIRST(&bus->pending_masters); + bus->bh =3D node->bh; + + QSIMPLEQ_REMOVE_HEAD(&bus->pending_masters, entry); + g_free(node); + qemu_bh_schedule(bus->bh); } =20 void i2c_bus_release(I2CBus *bus) { bus->bh =3D NULL; + + i2c_schedule_pending_master(bus); } =20 int i2c_start_recv(I2CBus *bus, uint8_t address) @@ -234,16 +251,6 @@ void i2c_end_transfer(I2CBus *bus) g_free(node); } bus->broadcast =3D false; - - if (!QSIMPLEQ_EMPTY(&bus->pending_masters)) { - I2CPendingMaster *node =3D QSIMPLEQ_FIRST(&bus->pending_masters); - bus->bh =3D node->bh; - - QSIMPLEQ_REMOVE_HEAD(&bus->pending_masters, entry); - g_free(node); - - qemu_bh_schedule(bus->bh); - } } =20 int i2c_send(I2CBus *bus, uint8_t data) --=20 2.39.1