From patchwork Mon Aug 22 09:15:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vaishnav Achath X-Patchwork-Id: 12950409 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 D37FFC3F6B0 for ; Mon, 22 Aug 2022 09:16:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234063AbiHVJQ4 (ORCPT ); Mon, 22 Aug 2022 05:16:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234599AbiHVJPy (ORCPT ); Mon, 22 Aug 2022 05:15:54 -0400 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 209E1286F2; Mon, 22 Aug 2022 02:15:41 -0700 (PDT) Received: from fllv0034.itg.ti.com ([10.64.40.246]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 27M9FaUN121375; Mon, 22 Aug 2022 04:15:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1661159736; bh=4RWmn9Vu1OlHjUmqPhU6tSBzfYbt3rOJpZXMAAaiX+w=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=NuVwIMSvZ6ZH0I95bUagB4dlPI77RKUHqPAqFr+E4PmjsS+sk3/0VQZdVKU6Sj+iS Qtb5tQbeJySFzu507Im1iLoq97l4H4YP2xetHw8xfgwsRgur2HSOH71UO73gCwqfG2 izvGG9Vfg0ToVeaD+FLaR6QR/fVzv0vSbqcZW/zI= Received: from DFLE112.ent.ti.com (dfle112.ent.ti.com [10.64.6.33]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 27M9Fa8q111278 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 22 Aug 2022 04:15:36 -0500 Received: from DFLE107.ent.ti.com (10.64.6.28) by DFLE112.ent.ti.com (10.64.6.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.6; Mon, 22 Aug 2022 04:15:36 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DFLE107.ent.ti.com (10.64.6.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.6 via Frontend Transport; Mon, 22 Aug 2022 04:15:36 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id 27M9FZuh069753; Mon, 22 Aug 2022 04:15:36 -0500 From: Vaishnav Achath To: , , , , , CC: , , Subject: [PATCH 2/2] spi: spi-omap2-mcspi: Use EOW interrupt for completion when DMA enabled Date: Mon, 22 Aug 2022 14:45:31 +0530 Message-ID: <20220822091531.27827-3-vaishnav.a@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220822091531.27827-1-vaishnav.a@ti.com> References: <20220822091531.27827-1-vaishnav.a@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org In MCSPI controller EOW interrupt is triggered when the channel has transmitted the set number of bytes in MCSPI_XFERLEVEL[31-16] WCNT, this can be used to signal the completion of a TX/RX when the internal FIFO is enabled, when DMA is enabled the internal FIFO is always enabled. Waiting for the DMA completion adds unpredictable delays due to the non-realtime completion calculation mechanism in k3-udma driver. This commit removes the dma_tx_completion and dma_rx_completion and relies on the MCSPI controller EOW interrupt to signal transaction completion.This fixes the real-time performance issues in master and slave mode when DMA was enabled which resulted from the DMA completion calculation delays. Since the MCSPI driver now uses internal mechanism to identify a transfer completion we disable the TX and RX DMA completion callback and remove DMA_PREP_INTERRUPT. Signed-off-by: Vaishnav Achath Reported-by: kernel test robot --- drivers/spi/spi-omap2-mcspi.c | 141 +++++++++------------------------- 1 file changed, 36 insertions(+), 105 deletions(-) diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index c48d02bb7013..8680465533e0 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -91,10 +91,6 @@ struct omap2_mcspi_dma { struct dma_chan *dma_tx; struct dma_chan *dma_rx; - - struct completion dma_tx_completion; - struct completion dma_rx_completion; - char dma_rx_ch_name[14]; char dma_tx_ch_name[14]; }; @@ -116,7 +112,7 @@ struct omap2_mcspi_regs { }; struct omap2_mcspi { - struct completion txdone; + struct completion txrxdone; struct spi_master *master; /* Virtual base address of the controller */ void __iomem *base; @@ -375,30 +371,6 @@ static int mcspi_wait_for_completion(struct omap2_mcspi *mcspi, return 0; } -static void omap2_mcspi_rx_callback(void *data) -{ - struct spi_device *spi = data; - struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); - struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select]; - - /* We must disable the DMA RX request */ - omap2_mcspi_set_dma_req(spi, 1, 0); - - complete(&mcspi_dma->dma_rx_completion); -} - -static void omap2_mcspi_tx_callback(void *data) -{ - struct spi_device *spi = data; - struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); - struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select]; - - /* We must disable the DMA TX request */ - omap2_mcspi_set_dma_req(spi, 0, 0); - - complete(&mcspi_dma->dma_tx_completion); -} - static void omap2_mcspi_tx_dma(struct spi_device *spi, struct spi_transfer *xfer, struct dma_slave_config cfg) @@ -413,12 +385,9 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi, dmaengine_slave_config(mcspi_dma->dma_tx, &cfg); tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl, - xfer->tx_sg.nents, - DMA_MEM_TO_DEV, - DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + xfer->tx_sg.nents, DMA_MEM_TO_DEV, DMA_CTRL_ACK); + if (tx) { - tx->callback = omap2_mcspi_tx_callback; - tx->callback_param = spi; dmaengine_submit(tx); } else { /* FIXME: fall back to PIO? */ @@ -500,11 +469,9 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer, } tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, sg_out[0], - out_mapped_nents[0], DMA_DEV_TO_MEM, - DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + out_mapped_nents[0], DMA_DEV_TO_MEM, DMA_CTRL_ACK); + if (tx) { - tx->callback = omap2_mcspi_rx_callback; - tx->callback_param = spi; dmaengine_submit(tx); } else { /* FIXME: fall back to PIO? */ @@ -513,10 +480,10 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer, dma_async_issue_pending(mcspi_dma->dma_rx); omap2_mcspi_set_dma_req(spi, 1, 1); - ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_rx_completion); + ret = mcspi_wait_for_completion(mcspi, &mcspi->txrxdone); + omap2_mcspi_set_dma_req(spi, 1, 0); if (ret || mcspi->slave_aborted) { dmaengine_terminate_sync(mcspi_dma->dma_rx); - omap2_mcspi_set_dma_req(spi, 1, 0); return 0; } @@ -587,8 +554,8 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) enum dma_slave_buswidth width; unsigned es; void __iomem *chstat_reg; - void __iomem *irqstat_reg; int wait_res; + int ret; mcspi = spi_master_get_devdata(spi->master); mcspi_dma = &mcspi->dma_channels[spi->chip_select]; @@ -618,68 +585,36 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) tx = xfer->tx_buf; mcspi->slave_aborted = false; - reinit_completion(&mcspi_dma->dma_tx_completion); - reinit_completion(&mcspi_dma->dma_rx_completion); - reinit_completion(&mcspi->txdone); - if (tx) { - /* Enable EOW IRQ to know end of tx in slave mode */ - if (spi_controller_is_slave(spi->master)) - mcspi_write_reg(spi->master, - OMAP2_MCSPI_IRQENABLE, - OMAP2_MCSPI_IRQSTATUS_EOW); + reinit_completion(&mcspi->txrxdone); + mcspi_write_reg(spi->master, OMAP2_MCSPI_IRQENABLE, OMAP2_MCSPI_IRQSTATUS_EOW); + if (tx) omap2_mcspi_tx_dma(spi, xfer, cfg); - } - if (rx != NULL) + if (rx) count = omap2_mcspi_rx_dma(spi, xfer, cfg, es); - if (tx != NULL) { - int ret; - - ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_tx_completion); - if (ret || mcspi->slave_aborted) { - dmaengine_terminate_sync(mcspi_dma->dma_tx); - omap2_mcspi_set_dma_req(spi, 0, 0); - return 0; - } - - if (spi_controller_is_slave(mcspi->master)) { - ret = mcspi_wait_for_completion(mcspi, &mcspi->txdone); - if (ret || mcspi->slave_aborted) - return 0; - } + ret = mcspi_wait_for_completion(mcspi, &mcspi->txrxdone); + omap2_mcspi_set_dma_req(spi, 0, 0); + if (ret || mcspi->slave_aborted) + return 0; + /* for TX_ONLY mode, be sure all words have shifted out */ + if (tx && !rx) { + chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0; if (mcspi->fifo_depth > 0) { - irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS; - - if (mcspi_wait_for_reg_bit(irqstat_reg, - OMAP2_MCSPI_IRQSTATUS_EOW) < 0) - dev_err(&spi->dev, "EOW timed out\n"); - - mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS, - OMAP2_MCSPI_IRQSTATUS_EOW); - } - - /* for TX_ONLY mode, be sure all words have shifted out */ - if (rx == NULL) { - chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0; - if (mcspi->fifo_depth > 0) { - wait_res = mcspi_wait_for_reg_bit(chstat_reg, - OMAP2_MCSPI_CHSTAT_TXFFE); - if (wait_res < 0) - dev_err(&spi->dev, "TXFFE timed out\n"); - } else { - wait_res = mcspi_wait_for_reg_bit(chstat_reg, - OMAP2_MCSPI_CHSTAT_TXS); - if (wait_res < 0) - dev_err(&spi->dev, "TXS timed out\n"); - } - if (wait_res >= 0 && - (mcspi_wait_for_reg_bit(chstat_reg, - OMAP2_MCSPI_CHSTAT_EOT) < 0)) - dev_err(&spi->dev, "EOT timed out\n"); + wait_res = mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXFFE); + if (wait_res < 0) + dev_err(&spi->dev, "TXFFE timed out\n"); + } else { + wait_res = mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_TXS); + if (wait_res < 0) + dev_err(&spi->dev, "TXS timed out\n"); } + if (wait_res >= 0 && (mcspi_wait_for_reg_bit(chstat_reg, + OMAP2_MCSPI_CHSTAT_EOT) < 0)) + dev_err(&spi->dev, "EOT timed out\n"); } + return count; } @@ -1010,9 +945,6 @@ static int omap2_mcspi_request_dma(struct omap2_mcspi *mcspi, mcspi_dma->dma_rx = NULL; } - init_completion(&mcspi_dma->dma_rx_completion); - init_completion(&mcspi_dma->dma_tx_completion); - no_dma: return ret; } @@ -1102,8 +1034,10 @@ static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data) /* Disable IRQ and wakeup slave xfer task */ mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQENABLE, 0); - if (irqstat & OMAP2_MCSPI_IRQSTATUS_EOW) - complete(&mcspi->txdone); + if (irqstat & OMAP2_MCSPI_IRQSTATUS_EOW) { + complete_all(&mcspi->txrxdone); + mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS, OMAP2_MCSPI_IRQSTATUS_EOW); + } return IRQ_HANDLED; } @@ -1111,12 +1045,9 @@ static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data) static int omap2_mcspi_slave_abort(struct spi_master *master) { struct omap2_mcspi *mcspi = spi_master_get_devdata(master); - struct omap2_mcspi_dma *mcspi_dma = mcspi->dma_channels; mcspi->slave_aborted = true; - complete(&mcspi_dma->dma_rx_completion); - complete(&mcspi_dma->dma_tx_completion); - complete(&mcspi->txdone); + complete_all(&mcspi->txrxdone); return 0; } @@ -1516,7 +1447,7 @@ static int omap2_mcspi_probe(struct platform_device *pdev) dev_err(&pdev->dev, "no irq resource found\n"); goto free_master; } - init_completion(&mcspi->txdone); + init_completion(&mcspi->txrxdone); status = devm_request_irq(&pdev->dev, status, omap2_mcspi_irq_handler, 0, pdev->name, mcspi);