From patchwork Mon Nov 30 14:14:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 335696 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=-21.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, 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 765EFC64E8A for ; Mon, 30 Nov 2020 14:16:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 286592087C for ; Mon, 30 Nov 2020 14:16:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727049AbgK3OQD (ORCPT ); Mon, 30 Nov 2020 09:16:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726661AbgK3OQC (ORCPT ); Mon, 30 Nov 2020 09:16:02 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 908BDC061A48 for ; Mon, 30 Nov 2020 06:14:45 -0800 (PST) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kjjwy-0007eA-02 for netdev@vger.kernel.org; Mon, 30 Nov 2020 15:14:44 +0100 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id B6FB859FAFB for ; Mon, 30 Nov 2020 14:14:37 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id 7922D59FAC4; Mon, 30 Nov 2020 14:14:34 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 850c4d2a; Mon, 30 Nov 2020 14:14:33 +0000 (UTC) From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Ursula Maplehurst , Thomas Kopp , Marc Kleine-Budde Subject: [net-next 03/14] can: mcp25xxfd: rx-path: reduce number of SPI core requests to set UINC bit Date: Mon, 30 Nov 2020 15:14:21 +0100 Message-Id: <20201130141432.278219-4-mkl@pengutronix.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201130141432.278219-1-mkl@pengutronix.de> References: <20201130141432.278219-1-mkl@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Ursula Maplehurst Reduce the number of separate SPI core requests when setting the UINC bit in the RX FIFO, and instead batch them up into a single SPI core request. Link: https://github.com/marckleinebudde/linux/issues/4 Link: https://lore.kernel.org/r/20201126132144.351154-3-mkl@pengutronix.de Tested-by: Thomas Kopp Signed-off-by: Ursula Maplehurst Signed-off-by: Marc Kleine-Budde --- .../net/can/spi/mcp251xfd/mcp251xfd-core.c | 51 ++++++++++++++++--- drivers/net/can/spi/mcp251xfd/mcp251xfd.h | 2 + 2 files changed, 45 insertions(+), 8 deletions(-) diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c index 476a2e4a1de8..c770733ecbcc 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c @@ -332,7 +332,7 @@ static void mcp251xfd_ring_init(struct mcp251xfd_priv *priv) u32 val; u16 addr; u8 len; - int i; + int i, j; /* TEF */ priv->tef.head = 0; @@ -370,6 +370,23 @@ static void mcp251xfd_ring_init(struct mcp251xfd_priv *priv) prev_rx_ring->obj_num; prev_rx_ring = rx_ring; + + /* FIFO increment RX tail pointer */ + addr = MCP251XFD_REG_FIFOCON(rx_ring->fifo_nr); + val = MCP251XFD_REG_FIFOCON_UINC; + len = mcp251xfd_cmd_prepare_write_reg(priv, &rx_ring->uinc_buf, + addr, val, val); + + for (j = 0; j < ARRAY_SIZE(rx_ring->uinc_xfer); j++) { + struct spi_transfer *xfer; + + xfer = &rx_ring->uinc_xfer[j]; + xfer->tx_buf = &rx_ring->uinc_buf; + xfer->len = len; + xfer->cs_change = 1; + xfer->cs_change_delay.value = 0; + xfer->cs_change_delay.unit = SPI_DELAY_UNIT_NSECS; + } } } @@ -1440,13 +1457,7 @@ mcp251xfd_handle_rxif_one(struct mcp251xfd_priv *priv, if (err) stats->rx_fifo_errors++; - ring->tail++; - - /* finally increment the RX pointer */ - return regmap_update_bits(priv->map_reg, - MCP251XFD_REG_FIFOCON(ring->fifo_nr), - GENMASK(15, 8), - MCP251XFD_REG_FIFOCON_UINC); + return 0; } static inline int @@ -1478,6 +1489,8 @@ mcp251xfd_handle_rxif_ring(struct mcp251xfd_priv *priv, return err; while ((len = mcp251xfd_get_rx_linear_len(ring))) { + struct spi_transfer *last_xfer; + rx_tail = mcp251xfd_get_rx_tail(ring); err = mcp251xfd_rx_obj_read(priv, ring, hw_rx_obj, @@ -1492,6 +1505,28 @@ mcp251xfd_handle_rxif_ring(struct mcp251xfd_priv *priv, if (err) return err; } + + /* Increment the RX FIFO tail pointer 'len' times in a + * single SPI message. + */ + ring->tail += len; + + /* Note: + * + * "cs_change == 1" on the last transfer results in an + * active chip select after the complete SPI + * message. This causes the controller to interpret + * the next register access as data. Temporary set + * "cs_change" of the last transfer to "0" to properly + * deactivate the chip select at the end of the + * message. + */ + last_xfer = &ring->uinc_xfer[len - 1]; + last_xfer->cs_change = 0; + err = spi_sync_transfer(priv->spi, ring->uinc_xfer, len); + last_xfer->cs_change = 1; + if (err) + return err; } return 0; diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h index c20c97d01072..97dc182e2b42 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h @@ -528,6 +528,8 @@ struct mcp251xfd_rx_ring { u8 obj_num; u8 obj_size; + union mcp251xfd_write_reg_buf uinc_buf; + struct spi_transfer uinc_xfer[MCP251XFD_RX_OBJ_NUM_MAX]; struct mcp251xfd_hw_rx_obj_canfd obj[]; };