From patchwork Tue Aug 2 05:48:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vaishnav Achath X-Patchwork-Id: 12934241 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 F361AC00140 for ; Tue, 2 Aug 2022 05:48:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231804AbiHBFsu (ORCPT ); Tue, 2 Aug 2022 01:48:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58942 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232951AbiHBFst (ORCPT ); Tue, 2 Aug 2022 01:48:49 -0400 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 582B41A3A8; Mon, 1 Aug 2022 22:48:47 -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 2725mb6Q009641; Tue, 2 Aug 2022 00:48:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1659419317; bh=8qM0HaK1XtUl0gg6PEXng5wHvX129CzzCPUs4eaT/jw=; h=From:To:CC:Subject:Date; b=mI94A7TEM3lg1NBqeHQoLngtkqSkV0EVdqOBxx2Bf+RyxLRCO90EMrdUhs+mMSAyZ VXSlko1mxJkEuY4T80ExIofjgbYlBZagHIewT5Cb6m7it/gSo2TfjyWHo2Mm/OQ+Wt OCURb0fEjrrWZxcflQsy09TVc0JyNK5/8Gz8diPk= Received: from DLEE109.ent.ti.com (dlee109.ent.ti.com [157.170.170.41]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 2725mbTl025204 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 2 Aug 2022 00:48:37 -0500 Received: from DLEE113.ent.ti.com (157.170.170.24) by DLEE109.ent.ti.com (157.170.170.41) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14; Tue, 2 Aug 2022 00:48:37 -0500 Received: from lelv0326.itg.ti.com (10.180.67.84) by DLEE113.ent.ti.com (157.170.170.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14 via Frontend Transport; Tue, 2 Aug 2022 00:48:37 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id 2725mZnR018555; Tue, 2 Aug 2022 00:48:36 -0500 From: Vaishnav Achath To: , , , CC: , , , , , Subject: [PATCH v3] dmaengine: ti: k3-udma: Reset UDMA_CHAN_RT byte counters to prevent overflow Date: Tue, 2 Aug 2022 11:18:35 +0530 Message-ID: <20220802054835.19482-1-vaishnav.a@ti.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org UDMA_CHAN_RT_*BCNT_REG stores the real-time channel bytecount statistics. These registers are 32-bit hardware counters and the driver uses these counters to monitor the operational progress status for a channel, when transferring more than 4GB of data it was observed that these counters overflow and completion calculation of a operation gets affected and the transfer hangs indefinitely. This commit adds changes to decrease the byte count for every complete transaction so that these registers never overflow and the proper byte count statistics is maintained for ongoing transaction by the RT counters. Earlier uc->bcnt used to maintain a count of the completed bytes at driver side, since the RT counters maintain the statistics of current transaction now, the maintenance of uc->bcnt is not necessary. Signed-off-by: Vaishnav Achath Acked-by: Peter Ujfalusi --- V2->V3 : * Remove unnecessary checks for uc->tchan and uc->rchan in udma_decrement_byte_counters() V1->V2 : * Update bcnt reset based on uc->desc->dir * change order of udma_decrement_byte_counters() to before udma_start() * update subsystem tag drivers/dma/ti/k3-udma.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c index 2f0d2c68c93c..fcfcde947b30 100644 --- a/drivers/dma/ti/k3-udma.c +++ b/drivers/dma/ti/k3-udma.c @@ -300,8 +300,6 @@ struct udma_chan { struct udma_tx_drain tx_drain; - u32 bcnt; /* number of bytes completed since the start of the channel */ - /* Channel configuration parameters */ struct udma_chan_config config; @@ -757,6 +755,20 @@ static void udma_reset_rings(struct udma_chan *uc) } } +static void udma_decrement_byte_counters(struct udma_chan *uc, u32 val) +{ + if (uc->desc->dir == DMA_DEV_TO_MEM) { + udma_rchanrt_write(uc, UDMA_CHAN_RT_BCNT_REG, val); + udma_rchanrt_write(uc, UDMA_CHAN_RT_SBCNT_REG, val); + udma_rchanrt_write(uc, UDMA_CHAN_RT_PEER_BCNT_REG, val); + } else { + udma_tchanrt_write(uc, UDMA_CHAN_RT_BCNT_REG, val); + udma_tchanrt_write(uc, UDMA_CHAN_RT_SBCNT_REG, val); + if (!uc->bchan) + udma_tchanrt_write(uc, UDMA_CHAN_RT_PEER_BCNT_REG, val); + } +} + static void udma_reset_counters(struct udma_chan *uc) { u32 val; @@ -790,8 +802,6 @@ static void udma_reset_counters(struct udma_chan *uc) val = udma_rchanrt_read(uc, UDMA_CHAN_RT_PEER_BCNT_REG); udma_rchanrt_write(uc, UDMA_CHAN_RT_PEER_BCNT_REG, val); } - - uc->bcnt = 0; } static int udma_reset_chan(struct udma_chan *uc, bool hard) @@ -1115,7 +1125,7 @@ static void udma_check_tx_completion(struct work_struct *work) if (uc->desc) { struct udma_desc *d = uc->desc; - uc->bcnt += d->residue; + udma_decrement_byte_counters(uc, d->residue); udma_start(uc); vchan_cookie_complete(&d->vd); break; @@ -1168,7 +1178,7 @@ static irqreturn_t udma_ring_irq_handler(int irq, void *data) vchan_cyclic_callback(&d->vd); } else { if (udma_is_desc_really_done(uc, d)) { - uc->bcnt += d->residue; + udma_decrement_byte_counters(uc, d->residue); udma_start(uc); vchan_cookie_complete(&d->vd); } else { @@ -1204,7 +1214,7 @@ static irqreturn_t udma_udma_irq_handler(int irq, void *data) vchan_cyclic_callback(&d->vd); } else { /* TODO: figure out the real amount of data */ - uc->bcnt += d->residue; + udma_decrement_byte_counters(uc, d->residue); udma_start(uc); vchan_cookie_complete(&d->vd); } @@ -3809,7 +3819,6 @@ static enum dma_status udma_tx_status(struct dma_chan *chan, bcnt = udma_tchanrt_read(uc, UDMA_CHAN_RT_BCNT_REG); } - bcnt -= uc->bcnt; if (bcnt && !(bcnt % uc->desc->residue)) residue = 0; else