From patchwork Sun Sep 20 11:23:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11787545 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3548E139A for ; Sun, 20 Sep 2020 11:32:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 27D6C20EDD for ; Sun, 20 Sep 2020 11:32:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726285AbgITLcY (ORCPT ); Sun, 20 Sep 2020 07:32:24 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:54028 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726314AbgITLcX (ORCPT ); Sun, 20 Sep 2020 07:32:23 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id E4D5E803073C; Sun, 20 Sep 2020 11:23:26 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id FYtquVonEStk; Sun, 20 Sep 2020 14:23:26 +0300 (MSK) From: Serge Semin To: Mark Brown CC: Serge Semin , Serge Semin , Alexey Malahov , Georgy Vlasov , Ramil Zaripov , Pavel Parkhomenko , Peter Ujfalusi , Andy Shevchenko , Andy Shevchenko , Feng Tang , Vinod Koul , , Subject: [PATCH v2 02/11] spi: dw-dma: Fail DMA-based transfer if no Tx-buffer specified Date: Sun, 20 Sep 2020 14:23:13 +0300 Message-ID: <20200920112322.24585-3-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200920112322.24585-1-Sergey.Semin@baikalelectronics.ru> References: <20200920112322.24585-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Since commit 46164fde6b78 ("spi: dw: Fix Rx-only DMA transfers") if DMA interface is enabled, then Tx-buffer must be available in each SPI transfer. It's required since in order to activate the incoming data reception either DMA or CPU must be pushing data out to the SPI bus. But the DW APB SSI DMA driver code is still left in state as if Tx-buffer might be optional, which is no longer true. Let's fix it so an error would be returned if no Tx-buffer detected and DMA Tx would be always enabled. Signed-off-by: Serge Semin --- drivers/spi/spi-dw-dma.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) diff --git a/drivers/spi/spi-dw-dma.c b/drivers/spi/spi-dw-dma.c index a7ff1e357f8b..1b013ac94a3f 100644 --- a/drivers/spi/spi-dw-dma.c +++ b/drivers/spi/spi-dw-dma.c @@ -262,9 +262,6 @@ dw_spi_dma_prepare_tx(struct dw_spi *dws, struct spi_transfer *xfer) struct dma_slave_config txconf; struct dma_async_tx_descriptor *txdesc; - if (!xfer->tx_buf) - return NULL; - memset(&txconf, 0, sizeof(txconf)); txconf.direction = DMA_MEM_TO_DEV; txconf.dst_addr = dws->dma_addr; @@ -383,17 +380,19 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws, static int dw_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer) { - u16 imr = 0, dma_ctrl = 0; + u16 imr, dma_ctrl; - if (xfer->tx_buf) - dma_ctrl |= SPI_DMA_TDMAE; + if (!xfer->tx_buf) + return -EINVAL; + + /* Set the DMA handshaking interface */ + dma_ctrl = SPI_DMA_TDMAE; if (xfer->rx_buf) dma_ctrl |= SPI_DMA_RDMAE; dw_writel(dws, DW_SPI_DMACR, dma_ctrl); /* Set the interrupt mask */ - if (xfer->tx_buf) - imr |= SPI_INT_TXOI; + imr = SPI_INT_TXOI; if (xfer->rx_buf) imr |= SPI_INT_RXUI | SPI_INT_RXOI; spi_umask_intr(dws, imr); @@ -412,6 +411,8 @@ static int dw_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer) /* Prepare the TX dma transfer */ txdesc = dw_spi_dma_prepare_tx(dws, xfer); + if (!txdesc) + return -EINVAL; /* Prepare the RX dma transfer */ rxdesc = dw_spi_dma_prepare_rx(dws, xfer); @@ -423,17 +424,15 @@ static int dw_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer) dma_async_issue_pending(dws->rxchan); } - if (txdesc) { - set_bit(TX_BUSY, &dws->dma_chan_busy); - dmaengine_submit(txdesc); - dma_async_issue_pending(dws->txchan); - } + set_bit(TX_BUSY, &dws->dma_chan_busy); + dmaengine_submit(txdesc); + dma_async_issue_pending(dws->txchan); ret = dw_spi_dma_wait(dws, xfer); if (ret) return ret; - if (txdesc && dws->master->cur_msg->status == -EINPROGRESS) { + if (dws->master->cur_msg->status == -EINPROGRESS) { ret = dw_spi_dma_wait_tx_done(dws, xfer); if (ret) return ret;