From patchwork Tue May 25 13:10:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roja Rani Yarubandi X-Patchwork-Id: 447594 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DAE9C47085 for ; Tue, 25 May 2021 13:12:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBF356140B for ; Tue, 25 May 2021 13:12:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233089AbhEYNNg (ORCPT ); Tue, 25 May 2021 09:13:36 -0400 Received: from alexa-out.qualcomm.com ([129.46.98.28]:36007 "EHLO alexa-out.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233058AbhEYNN0 (ORCPT ); Tue, 25 May 2021 09:13:26 -0400 Received: from ironmsg-lv-alpha.qualcomm.com ([10.47.202.13]) by alexa-out.qualcomm.com with ESMTP; 25 May 2021 06:11:43 -0700 X-QCInternal: smtphost Received: from ironmsg01-blr.qualcomm.com ([10.86.208.130]) by ironmsg-lv-alpha.qualcomm.com with ESMTP/TLS/AES256-SHA; 25 May 2021 06:11:41 -0700 X-QCInternal: smtphost Received: from c-rojay-linux.qualcomm.com ([10.206.21.80]) by ironmsg01-blr.qualcomm.com with ESMTP; 25 May 2021 18:40:57 +0530 Received: by c-rojay-linux.qualcomm.com (Postfix, from userid 88981) id 3A5833359; Tue, 25 May 2021 18:40:56 +0530 (IST) From: Roja Rani Yarubandi To: wsa@kernel.org Cc: swboyd@chromium.org, dianders@chromium.org, saiprakash.ranjan@codeaurora.org, gregkh@linuxfoundation.org, mka@chromium.org, skananth@codeaurora.org, msavaliy@qti.qualcomm.com, skakit@codeaurora.org, rnayak@codeaurora.org, agross@kernel.org, bjorn.andersson@linaro.org, linux-arm-msm@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, sumit.semwal@linaro.org, linux-media@vger.kernel.org, Roja Rani Yarubandi Subject: [PATCH V11 1/2] i2c: i2c-qcom-geni: Add shutdown callback for i2c Date: Tue, 25 May 2021 18:40:50 +0530 Message-Id: <20210525131051.31250-2-rojay@codeaurora.org> X-Mailer: git-send-email 2.29.0 In-Reply-To: <20210525131051.31250-1-rojay@codeaurora.org> References: <20210525131051.31250-1-rojay@codeaurora.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org If the hardware is still accessing memory after SMMU translation is disabled (as part of smmu shutdown callback), then the IOVAs (I/O virtual address) which it was using will go on the bus as the physical addresses which will result in unknown crashes like NoC/interconnect errors. So, implement shutdown callback for i2c driver to suspend the bus during system "reboot" or "shutdown". Fixes: 37692de5d523 ("i2c: i2c-qcom-geni: Add bus driver for the Qualcomm GENI I2C controller") Signed-off-by: Roja Rani Yarubandi --- Changes in V2: - As per Stephen's comments added seperate function for stop transfer, fixed minor nitpicks. - As per Stephen's comments, changed commit text. Changes in V3: - As per Stephen's comments, squashed patch 1 into patch 2, added Fixes tag. - As per Akash's comments, included FIFO case in stop_xfer, fixed minor nitpicks. Changes in V4: - As per Stephen's comments cleaned up geni_i2c_stop_xfer function, added dma_buf in geni_i2c_dev struct to call i2c_put_dma_safe_msg_buf() from other functions, removed "iova" check in geni_se_rx_dma_unprep() and geni_se_tx_dma_unprep() functions. - Added two helper functions geni_i2c_rx_one_msg_done() and geni_i2c_tx_one_msg_done() to unwrap the things after rx/tx FIFO/DMA transfers, so that the same can be used in geni_i2c_stop_xfer() function during shutdown callback. Updated commit text accordingly. - Checking whether it is tx/rx transfer using I2C_M_RD which is valid for both FIFO and DMA cases, so dropped DMA_RX_ACTIVE and DMA_TX_ACTIVE bit checking Changes in V5: - As per Stephen's comments, added spin_lock_irqsave & spin_unlock_irqsave in geni_i2c_stop_xfer() function. Changes in V6: - As per Stephen's comments, taken care of unsafe lock order in geni_i2c_stop_xfer(). - Moved spin_lock/unlock to geni_i2c_rx_msg_cleanup() and geni_i2c_tx_msg_cleanup() functions. Changes in V7: - No changes Changes in V8: - As per Wolfram Sang comment, removed goto and modified geni_i2c_stop_xfer() accordingly. Changes in V9: - Fixed possbile race by protecting gi2c->cur and calling geni_i2c_abort_xfer() with adding another parameter to differentiate from which sequence is the geni_i2c_abort_xfer() called and handle the spin_lock/spin_unlock accordingly inside geni_i2c_abort_xfer(). For this added two macros ABORT_XFER and STOP_AND_ABORT_XFER. - Added a bool variable "stop_xfer" in geni_i2c_dev struct, used to put stop to upcoming geni_i2c_rx_one_msg() and geni_i2c_tx_one_msg() calls once we recieve the shutdown call. - Added gi2c->cur == NULL check in geni_i2c_irq() to not to process the irq even if any transfer is queued and shutdown to HW received. Changes in V10: - As per Stephen's comments, removed ongoing transfers flush and only suspending i2c bus in shutdown callback. - Also removed all other changes which have been made for ongoing transfers flush, handling race issues etc., during shutdown callback. - Updated commit text accordingly. Changes in V11: - As per Stephen's comments, suspended bus in shutdown call using i2c_mark_adapter_suspended() call to block any future transfers. drivers/i2c/busses/i2c-qcom-geni.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index 214b4c913a13..c3ae66ba6345 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -650,6 +650,14 @@ static int geni_i2c_remove(struct platform_device *pdev) return 0; } +static void geni_i2c_shutdown(struct platform_device *pdev) +{ + struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev); + + /* Make client i2c transfers start failing */ + i2c_mark_adapter_suspended(&gi2c->adap); +} + static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev) { int ret; @@ -714,6 +722,7 @@ MODULE_DEVICE_TABLE(of, geni_i2c_dt_match); static struct platform_driver geni_i2c_driver = { .probe = geni_i2c_probe, .remove = geni_i2c_remove, + .shutdown = geni_i2c_shutdown, .driver = { .name = "geni_i2c", .pm = &geni_i2c_pm_ops,