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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
  to recall all the context.
  
  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