From patchwork Tue Sep 27 11:21:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincent Whitchurch X-Patchwork-Id: 610898 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 D970FC6FA8E for ; Tue, 27 Sep 2022 11:23:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230153AbiI0LXv (ORCPT ); Tue, 27 Sep 2022 07:23:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231393AbiI0LXD (ORCPT ); Tue, 27 Sep 2022 07:23:03 -0400 Received: from smtp1.axis.com (smtp1.axis.com [195.60.68.17]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2C5613A951; Tue, 27 Sep 2022 04:21:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axis.com; q=dns/txt; s=axis-central1; t=1664277702; x=1695813702; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=TrQtsuqQ4EnLgm0F7EqTy/mbaX8OOSSxYGg4dteSuwI=; b=EX9w+PF1n6PQ+dm4r/EnyxJBqxrgQ9yW6ZOWwDXUAjaJ5fkO/ipDbNNV /Pj6D67jGqBgeDpjKjOeuu4OqfmvFKmjp226snUg7TjDDSC8GoVwwxOGs bk8pEabpSBP5kK8DeRCjbwGsDPo7K7QWOblViIrqz3/tvTzSdHrsbxFVL 6b6wDMTXFNSt2iv5fvg0v6G8LPkmrVQm5eKuHEn+/N+TjDyatfhviLbQ6 MsrCFJvwgl66q1RpU8aoNmayrFW0ZnH9k+GDqRqpC07/MqblQY+yXg4JI HAbuApAwGbeae8ToB3pn8ZtRr7GBQZBxj5lIWHYvrdLe6R4gDWdNq5MKG A==; From: Vincent Whitchurch To: , , CC: , Vincent Whitchurch , , , , , Subject: [PATCH v2 4/4] spi: s3c64xx: Fix large transfers with DMA Date: Tue, 27 Sep 2022 13:21:17 +0200 Message-ID: <20220927112117.77599-5-vincent.whitchurch@axis.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220927112117.77599-1-vincent.whitchurch@axis.com> References: <20220927112117.77599-1-vincent.whitchurch@axis.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org The COUNT_VALUE in the PACKET_CNT register is 16-bit so the maximum value is 65535. Asking the driver to transfer a larger size currently leads to the DMA transfer timing out. Implement ->max_transfer_size() and have the core split the transfer as needed. Fixes: 230d42d422e7 ("spi: Add s3c64xx SPI Controller driver") Signed-off-by: Vincent Whitchurch --- drivers/spi/spi-s3c64xx.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 651c35dd9124..71d324ec9a70 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -84,6 +84,7 @@ #define S3C64XX_SPI_ST_TX_FIFORDY (1<<0) #define S3C64XX_SPI_PACKET_CNT_EN (1<<16) +#define S3C64XX_SPI_PACKET_CNT_MASK GENMASK(15, 0) #define S3C64XX_SPI_PND_TX_UNDERRUN_CLR (1<<4) #define S3C64XX_SPI_PND_TX_OVERRUN_CLR (1<<3) @@ -711,6 +712,13 @@ static int s3c64xx_spi_prepare_message(struct spi_master *master, return 0; } +static size_t s3c64xx_spi_max_transfer_size(struct spi_device *spi) +{ + struct spi_controller *ctlr = spi->controller; + + return ctlr->can_dma ? S3C64XX_SPI_PACKET_CNT_MASK : SIZE_MAX; +} + static int s3c64xx_spi_transfer_one(struct spi_master *master, struct spi_device *spi, struct spi_transfer *xfer) @@ -1152,6 +1160,7 @@ static int s3c64xx_spi_probe(struct platform_device *pdev) master->unprepare_transfer_hardware = s3c64xx_spi_unprepare_transfer; master->prepare_message = s3c64xx_spi_prepare_message; master->transfer_one = s3c64xx_spi_transfer_one; + master->max_transfer_size = s3c64xx_spi_max_transfer_size; master->num_chipselect = sci->num_cs; master->use_gpio_descriptors = true; master->dma_alignment = 8;