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From:   Walker Chen <walker.chen@starfivetech.com>
To:     Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
        Vinod Koul <vkoul@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor.dooley@microchip.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        "Emil Renner Berthing" <emil.renner.berthing@canonical.com>,
        Walker Chen <walker.chen@starfivetech.com>
CC:     <dmaengine@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-riscv@lists.infradead.org>
Subject: [PATCH v6 3/4] dmaengine: dw-axi-dmac: Increase polling time to DMA transmission completion status
Date:   Wed, 22 Mar 2023 17:48:19 +0800
Message-ID: <20230322094820.24738-4-walker.chen@starfivetech.com>
In-Reply-To: <20230322094820.24738-1-walker.chen@starfivetech.com>
References: <20230322094820.24738-1-walker.chen@starfivetech.com>
MIME-Version: 1.0
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The bit DMAC_CHEN[0] is automatically cleared by hardware to disable the
channel after the last AMBA transfer of the DMA transfer to the
destination has completed. Software can therefore poll this bit to
determine when this channel is free for a new DMA transfer.
This time requires at least 40 milliseconds on JH7110 SoC, otherwise an
error message 'failed to stop' will be reported.

Signed-off-by: Walker Chen <walker.chen@starfivetech.com>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index 6cfcb541d8c3..6937cc0c0b65 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -1147,7 +1147,7 @@ static int dma_chan_terminate_all(struct dma_chan *dchan)
 	axi_chan_disable(chan);
 
 	ret = readl_poll_timeout_atomic(chan->chip->regs + DMAC_CHEN, val,
-					!(val & chan_active), 1000, 10000);
+					!(val & chan_active), 1000, 50000);
 	if (ret == -ETIMEDOUT)
 		dev_warn(dchan2dev(dchan),
 			 "%s failed to stop\n", axi_chan_name(chan));
-- 
2.17.1