From mboxrd@z Thu Jan 1 00:00:00 1970 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 190BCC433FE for ; Thu, 13 Oct 2022 00:26:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230311AbiJMAZ7 (ORCPT ); Wed, 12 Oct 2022 20:25:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231169AbiJMAX4 (ORCPT ); Wed, 12 Oct 2022 20:23:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD0DC12C89A; Wed, 12 Oct 2022 17:22:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 82440615BE; Thu, 13 Oct 2022 00:21:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2CB57C433D6; Thu, 13 Oct 2022 00:21:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1665620509; bh=6xyclav8Mn6Z5DBx4PeLkb663P0y9XtwnIcCPni89VI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eMATqoy0XNS31d9jcZ2ewozbhYO18JNwLjpBZTZJlHtWHsWLpWrJjoSCT0pp/TeOt JjGo57khjSuw0gBQBaMsYEnUqt0wBkA2nmGNZRxdPSuUhdjg7YdclxqXpNfCbBKwu7 XiAeMBEIAKig9p8Aj0I0t4pbyklyfK2GxK79Qw7X/Si5SUe7o7seb13WO0B6Rb8iqX rMh38bZ5z5Nm/bDftcBXLYWYkAHrH2zdRukV3QAHX6WxXn0eQuemEE0lC8NSQWdMZ7 BZIlGmxElNSSiQ6R8QLGXCJWB6suq9uvdA09QJUElWSzpzW0d3vj4gCY6XqTSK189h Fm8EEbYOZ3y0Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vaishnav Achath , Peter Ujfalusi , Vinod Koul , Sasha Levin , dmaengine@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 07/47] dmaengine: ti: k3-udma: Reset UDMA_CHAN_RT byte counters to prevent overflow Date: Wed, 12 Oct 2022 20:20:42 -0400 Message-Id: <20221013002124.1894077-7-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221013002124.1894077-1-sashal@kernel.org> References: <20221013002124.1894077-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vaishnav Achath [ Upstream commit 7c94dcfa8fcff2dba53915f1dabfee49a3df8b88 ] 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 Link: https://lore.kernel.org/r/20220802054835.19482-1-vaishnav.a@ti.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- 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 041d8e32d630..75f2a0006c73 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); } @@ -3811,7 +3821,6 @@ 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 -- 2.35.1