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Date: Thu, 22 Jun 2023 13:32:04 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Maxim Kochetkov <fido_max@inbox.ru>
Cc: netdev@vger.kernel.org, Robert Hancock <robert.hancock@calian.com>,
 Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>, "David S. Miller"
 <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Paolo Abeni
 <pabeni@redhat.com>, Michal Simek <michal.simek@amd.com>, Andre Przywara
 <andre.przywara@arm.com>, linux-arm-kernel@lists.infradead.org,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 1/1] net: axienet: Move reset before 64-bit DMA
 detection
Message-ID: <20230622133204.2ba95c21@kernel.org>
In-Reply-To: <20230622192245.116864-1-fido_max@inbox.ru>
References: <20230622192245.116864-1-fido_max@inbox.ru>
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On Thu, 22 Jun 2023 22:22:45 +0300 Maxim Kochetkov wrote:
> 64-bit DMA detection will fail if axienet was started before (by boot
> loader, boot ROM, etc). In this state axienet will not start properly.
> XAXIDMA_TX_CDESC_OFFSET + 4 register (MM2S_CURDESC_MSB) is used to detect
> 64-bit DMA capability here. But datasheet says: When DMACR.RS is 1
> (axienet is in enabled state), CURDESC_PTR becomes Read Only (RO) and
> is used to fetch the first descriptor. So iowrite32()/ioread32() trick
> to this register to detect 64-bit DMA will not work.
> So move axienet reset before 64-bit DMA detection.
> 
> Fixes: f735c40ed93c ("net: axienet: Autodetect 64-bit DMA capability")
> Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
> Reviewed-by: Robert Hancock <robert.hancock@calian.com>
> Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>

Quoting documentation:

  Resending after review
  ~~~~~~~~~~~~~~~~~~~~~~
  
  Allow at least 24 hours to pass between postings. This will ensure reviewers
  from all geographical locations have a chance to chime in. Do not wait
  too long (weeks) between postings either as it will make it harder for reviewers
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  Make sure you address all the feedback in your new posting. Do not post a new
  version of the code if the discussion about the previous version is still
  ongoing, unless directly instructed by a reviewer.
  
See: https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#resending-after-review