From patchwork Wed Mar 22 16:49:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Charles Keepax X-Patchwork-Id: 13184333 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 alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1574AC76196 for ; Wed, 22 Mar 2023 16:51:57 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id AF7CFEAF; Wed, 22 Mar 2023 17:51:03 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz AF7CFEAF DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1679503913; bh=Wjvaj4Q1DNsLS5JhNdWkktL6OlZ7R4Ran1Bpp8B9ykc=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Archive: List-Help:List-Owner:List-Post:List-Subscribe:List-Unsubscribe: From:Reply-To:Cc:From; b=pKL7Bqk0nYd70HDoGTtx6hzA+tm/yRxnKcYh9lPj9JXypCT0Vz87Txy0bdySTbelt qYnyP4Kw3HDCfZnmr9PhWlaib2PeQB2+SHFkBvwyC79jE9QlwecZQI25NiaKSvoZmK b4gdLcF/KG+wD1BjEriG516TS/5yyTT1qYuTqTJI= Received: from mailman-core.alsa-project.org (mailman-core.alsa-project.org [10.254.200.10]) by alsa1.perex.cz (Postfix) with ESMTP id 0EF36F80529; Wed, 22 Mar 2023 17:50:11 +0100 (CET) To: Subject: [PATCH v2 3/3] soundwire: bus: Update sdw_nread/nwrite_no_pm to handle page boundaries Date: Wed, 22 Mar 2023 16:49:48 +0000 In-Reply-To: <20230322164948.566962-1-ckeepax@opensource.cirrus.com> References: <20230322164948.566962-1-ckeepax@opensource.cirrus.com> X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-alsa-devel.alsa-project.org-0; header-match-alsa-devel.alsa-project.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.8 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <167950380993.26.14208364759735193730@mailman-core.alsa-project.org> X-Patchwork-Original-From: Charles Keepax via Alsa-devel From: Charles Keepax Reply-To: Charles Keepax Cc: yung-chuan.liao@linux.intel.com, pierre-louis.bossart@linux.intel.com, sanyog.r.kale@intel.com, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, patches@opensource.cirrus.com Content-Disposition: inline Currently issuing a sdw_nread/nwrite_no_pm across a page boundary will silently fail to write correctly as nothing updates the page registers, meaning the same page of the chip will get rewritten with each successive page of data. As the sdw_msg structure contains page information it seems reasonable that a single sdw_msg should always be within one page. It is also mostly simpler to handle the paging at the bus level rather than each master having to handle it in their xfer_msg callback. As such add handling to the bus code to split up a transfer into multiple sdw_msg's when they go across page boundaries. Signed-off-by: Charles Keepax --- Changes since v1: - Switch from min to min_t to avoid the build issues on MIPs/i386 - Added comments to the kernel doc to say that large transactions will be broken up. Thanks, Charles drivers/soundwire/bus.c | 63 +++++++++++++++++++++++++---------------- 1 file changed, 39 insertions(+), 24 deletions(-) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index f1ffb8e0839dd..e157a39a82ce5 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -386,27 +386,46 @@ int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave, * Read/Write IO functions. */ +static int sdw_ntransfer_no_pm(struct sdw_slave *slave, u32 addr, u8 flags, + size_t count, u8 *val) +{ + struct sdw_msg msg; + size_t size; + int ret; + + while (count) { + // Only handle bytes up to next page boundary + size = min_t(size_t, count, (SDW_REGADDR + 1) - (addr & SDW_REGADDR)); + + ret = sdw_fill_msg(&msg, slave, addr, size, slave->dev_num, flags, val); + if (ret < 0) + return ret; + + ret = sdw_transfer(slave->bus, &msg); + if (ret < 0 && !slave->is_mockup_device) + return ret; + + addr += size; + val += size; + count -= size; + } + + return 0; +} + /** * sdw_nread_no_pm() - Read "n" contiguous SDW Slave registers with no PM * @slave: SDW Slave * @addr: Register address * @count: length * @val: Buffer for values to be read + * + * Note that if the message crosses a page boundary each page will be + * transferred under a separate invocation of the msg_lock. */ int sdw_nread_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) { - struct sdw_msg msg; - int ret; - - ret = sdw_fill_msg(&msg, slave, addr, count, - slave->dev_num, SDW_MSG_FLAG_READ, val); - if (ret < 0) - return ret; - - ret = sdw_transfer(slave->bus, &msg); - if (slave->is_mockup_device) - ret = 0; - return ret; + return sdw_ntransfer_no_pm(slave, addr, SDW_MSG_FLAG_READ, count, val); } EXPORT_SYMBOL(sdw_nread_no_pm); @@ -416,21 +435,13 @@ EXPORT_SYMBOL(sdw_nread_no_pm); * @addr: Register address * @count: length * @val: Buffer for values to be written + * + * Note that if the message crosses a page boundary each page will be + * transferred under a separate invocation of the msg_lock. */ int sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val) { - struct sdw_msg msg; - int ret; - - ret = sdw_fill_msg(&msg, slave, addr, count, - slave->dev_num, SDW_MSG_FLAG_WRITE, (u8 *)val); - if (ret < 0) - return ret; - - ret = sdw_transfer(slave->bus, &msg); - if (slave->is_mockup_device) - ret = 0; - return ret; + return sdw_ntransfer_no_pm(slave, addr, SDW_MSG_FLAG_WRITE, count, (u8 *)val); } EXPORT_SYMBOL(sdw_nwrite_no_pm); @@ -566,6 +577,8 @@ EXPORT_SYMBOL(sdw_update); * * This version of the function will take a PM reference to the slave * device. + * Note that if the message crosses a page boundary each page will be + * transferred under a separate invocation of the msg_lock. */ int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) { @@ -593,6 +606,8 @@ EXPORT_SYMBOL(sdw_nread); * * This version of the function will take a PM reference to the slave * device. + * Note that if the message crosses a page boundary each page will be + * transferred under a separate invocation of the msg_lock. */ int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val) {