From patchwork Wed Mar 1 16:56:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?C=C3=A9dric_Le_Goater?= X-Patchwork-Id: 13156244 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C2DF7C64ED6 for ; Wed, 1 Mar 2023 16:58:52 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pXPl2-0000g7-Kx; Wed, 01 Mar 2023 11:56:48 -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 1pXPl0-0000eW-I6; Wed, 01 Mar 2023 11:56:46 -0500 Received: from gandalf.ozlabs.org ([150.107.74.76]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pXPky-0007cv-LV; Wed, 01 Mar 2023 11:56:46 -0500 Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4PRgPK57Vbz4x7x; Thu, 2 Mar 2023 03:56:37 +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 4PRgPG5GS4z4x1R; Thu, 2 Mar 2023 03:56:34 +1100 (AEDT) From: =?utf-8?q?C=C3=A9dric_Le_Goater?= To: qemu-arm@nongnu.org, qemu-devel@nongnu.org Cc: Peter Maydell , Joel Stanley , Andrew Jeffery , Klaus Jensen , Corey Minyard , =?utf-8?q?C=C3=A9dric_Le_Goater?= Subject: [PATCH v2 02/11] hw/i2c: only schedule pending master when bus is idle Date: Wed, 1 Mar 2023 17:56:10 +0100 Message-Id: <20230301165619.2171090-3-clg@kaod.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230301165619.2171090-1-clg@kaod.org> References: <20230301165619.2171090-1-clg@kaod.org> MIME-Version: 1.0 Received-SPF: pass client-ip=150.107.74.76; envelope-from=SRS0=znpK=6Z=kaod.org=clg@ozlabs.org; helo=gandalf.ozlabs.org X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org 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: Cédric 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); +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); } 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) void i2c_bus_master(I2CBus *bus, QEMUBH *bh) { - if (i2c_bus_busy(bus)) { - I2CPendingMaster *node = g_new(struct I2CPendingMaster, 1); - node->bh = bh; + I2CPendingMaster *node = g_new(struct I2CPendingMaster, 1); + node->bh = bh; + + QSIMPLEQ_INSERT_TAIL(&bus->pending_masters, node, entry); +} + +void i2c_schedule_pending_master(I2CBus *bus) +{ + I2CPendingMaster *node; - 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; + } + if (QSIMPLEQ_EMPTY(&bus->pending_masters)) { return; } - bus->bh = bh; + node = QSIMPLEQ_FIRST(&bus->pending_masters); + bus->bh = node->bh; + + QSIMPLEQ_REMOVE_HEAD(&bus->pending_masters, entry); + g_free(node); + qemu_bh_schedule(bus->bh); } void i2c_bus_release(I2CBus *bus) { bus->bh = NULL; + + i2c_schedule_pending_master(bus); } int i2c_start_recv(I2CBus *bus, uint8_t address) @@ -234,16 +251,6 @@ void i2c_end_transfer(I2CBus *bus) g_free(node); } bus->broadcast = false; - - if (!QSIMPLEQ_EMPTY(&bus->pending_masters)) { - I2CPendingMaster *node = QSIMPLEQ_FIRST(&bus->pending_masters); - bus->bh = node->bh; - - QSIMPLEQ_REMOVE_HEAD(&bus->pending_masters, entry); - g_free(node); - - qemu_bh_schedule(bus->bh); - } } int i2c_send(I2CBus *bus, uint8_t data)