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Message-ID: <97c24824-d487-e377-3ef6-287bc5e0c0d6@sifive.com>
Date:   Thu, 21 Jul 2022 23:16:26 +0100
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Subject: Re: [PATCH 1/3] dmaengine: dw-axi-dmac: dump channel registers on
 error
Content-Language: en-GB
To:     Vinod Koul <vkoul@kernel.org>
Cc:     dmaengine@vger.kernel.org, Eugeniy.Paltsev@synopsys.com,
        linux-kernel@vger.kernel.org,
        Sudip Mukherjee <sudip.mukherjee@sifive.com>,
        Jude Onyenegecha <jude.onyenegecha@sifive.com>
References: <20220708170153.269991-1-ben.dooks@sifive.com>
 <20220708170153.269991-2-ben.dooks@sifive.com> <YtlG6hdTJPIDBk9Y@matsya>
From:   Ben Dooks <ben.dooks@sifive.com>
In-Reply-To: <YtlG6hdTJPIDBk9Y@matsya>
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Precedence: bulk

On 21/07/2022 13:30, Vinod Koul wrote:
> On 08-07-22, 18:01, Ben Dooks wrote:
>> On channel error, dump the channel register state before
>> the channel's LLI entries to see what the controller was
>> actually doing when the error happend.
>>
>> Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
>> ---
>>   .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 28 +++++++++++++++++++
>>   1 file changed, 28 insertions(+)
>>
>> 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 e9c9bcb1f5c2..75c537153e92 100644
>> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
>> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
>> @@ -79,6 +79,20 @@ axi_chan_iowrite64(struct axi_dma_chan *chan, u32 reg, u64 val)
>>   	iowrite32(upper_32_bits(val), chan->chan_regs + reg + 4);
>>   }
>>   
>> +static inline u64
>> +axi_chan_ioread64(struct axi_dma_chan *chan, u32 reg)
>> +{
>> +	u32 high, low;
>> +	u64 result;
>> +
>> +	low = ioread32(chan->chan_regs + reg);
>> +	high = ioread32(chan->chan_regs + reg + 4);
>> +
>> +	result = low;
>> +	result |= (u64)high << 32;
>> +	return result;
>> +}
> 
> Better to use helpers like lo_hi_readq()?

Will go check on those, thanks.