From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out203-205-221-191.mail.qq.com (out203-205-221-191.mail.qq.com [203.205.221.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 41C2925782A; Wed, 10 Sep 2025 10:47:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.205.221.191 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757501252; cv=none; b=PVLnzzEmOWvjvX5DvxfyaDNk172iglCXGExODEKZ4yW6FNprUXzP5QXSgHClXEkZZVvs/maJ8sysHR+PiM3Qh9XlM3dkaalyOo7lUcWQWFFQ0Rp5H9EL/JGDQ8rr1J/gCtcnUK5Rk9zbZgtbsVUZHVQV1wqeDQZ3WBFc9xBoo08= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757501252; c=relaxed/simple; bh=vuDuae618+G9GIUKKhfT2gpIoatwCsXfX9KM+fgvIWg=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ov4ZXYDN/PhDtUArlh2We80Foi4xxEOArdeQj6yRywKJxI7tguffcw3GRYTadfnvOeTpS0hC9AmNATzBnRxVNa7V7rlfJegIUJY39igiIvSEunkUojgZKtRccD1Hoh3kF9xGyM0p59DgHeJIQcbQ9hfniZjwqxwtfndApQiq97g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foxmail.com; spf=pass smtp.mailfrom=foxmail.com; dkim=pass (1024-bit key) header.d=foxmail.com header.i=@foxmail.com header.b=UKcOtrWe; arc=none smtp.client-ip=203.205.221.191 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foxmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=foxmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=foxmail.com header.i=@foxmail.com header.b="UKcOtrWe" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foxmail.com; s=s201512; t=1757500940; bh=2g9SqMhLUUY5OWEkbJI62B9o1oK6Cw9puvU0A/SCA4o=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=UKcOtrWeRpFVvSeF5GCNO133+5B6ZvqaXNXzV45vA3lJvkzVtzFWbiWnBOx/AezUZ kMIyisSIVdUV0F9VZd6S67kmAx80S1MS+KqDzlYF4m9ffw9tfsvqdJiJN4J6aJUgqU L2qBiOjvH1drJje0rA5tTn5QaYJ6SETm0WwqSVw0= Received: from localhost ([112.94.75.165]) by newxmesmtplogicsvrsza56-0.qq.com (NewEsmtp) with SMTP id A929FED7; Wed, 10 Sep 2025 18:42:18 +0800 X-QQ-mid: xmsmtpt1757500938tef4mg7kx Message-ID: X-QQ-XMAILINFO: OGZxhFXqN7PJ0OGUSKzaot3PkSIPfgVcLkJCNRpHiuJ/wDe1agEPYkkDgLl2Hi VOLH3oLeXitQpuBvQSjVDLTenk7gOXKMWl5lIUdIurYWrfPcJfqoxIlMbwDa0NCVvD/fpfwctQ4W dlK9X4VxXrG7MZypC2CsplwMvnT0QSoTIRbDK/PMKORm4o/XfhIUQzRmmgh1p6zV9KMUBUDDlxxe 7QiAGhORxfs6JdFSuF1CK/yMvtm3LKEeWHFAOkrOtx+/pQlaQ1KvAkMrnnQ0kofZ+7DM+METOhsF J0A1iiFDrnSTAK6HqAfofrs00ucqqsMDGFwHyxDy58hE0EC4s2DjhkNvLFOWC+i7EVgr5krq/Xsw jkbCVMlOSlPDeoU/ld01iXgQz+A8thbNZNMkJUeN4HQpFsLa2AMOet7cnlAmmr+EIFlGZseu13OX p3EX36p5+2qlaV2ZSSqSjj5lxzQRmefkqiQTjai6y80FGFidMEQsOnwil/dqtAoA5lg9Btk/mgSr IzLe9cdt2rPWbMaB36jw75vSDnopXHJTlmmyAHKei+sQgpdV/E/ZCvWG+stiNU5e0h+6EmsXn23S xl6rZr63f7g/xOceAsyUYfcnG/qW7YR3qcT0dqdHS+BK5ZWJGOmKG+wa+RTDypNQrsjutbM3DC0v CIZi00R9lMW3QWiloZRV1r5MM3JkInK9GunpWu+qwMnHMsb/tBCqS+3U9IfWSMMROzRHWEJPdYLX gsj0D3vQ4jaYVaAUGpvKNwl9rW8zP3F30rm6CoHC06oNSDol+pZKrCf7gAu+8LCzZ03K+GrXoHk5 uFcVtNUdpTenn9iFEjhgpP9nvOTWOHyNxxeqjTDhgqaR0V+sMwduna4mUAeKmLzyfwCX1SLkZ98Y jwyV3LptUlbJY901E7btNys4ibMQqCqYb0x42NGAwncT97apaNR8dB5BltdiakC2+Ks5Em5Siobs Fr7wWd2LPZgHgdvQMwvFosqJk5CsFqEnf+SEGw9lEVTd8xbCkqnC5GHvpJ+CgYdSTNCuzSJsRerA cL9uGeROqA7nvG09ZHTetWJgw1ONKke/Z2AYJAxw== X-QQ-XMRINFO: M/715EihBoGSf6IYSX1iLFg= Date: Wed, 10 Sep 2025 18:42:18 +0800 From: Conley Lee To: Jakub Kicinski Cc: vkoul@kernel.org, davem@davemloft.net, wens@csie.org, mripard@kernel.org, netdev@vger.kernel.org, dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: ethernet: sun4i-emac: free dma descriptor X-OQ-MSGID: <20250910104218.GA1760035@ubuntu-server> References: <20250904072446.5563130d@kernel.org> <20250908132615.6a2507ed@kernel.org> <20250909181547.0782840f@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250909181547.0782840f@kernel.org> On 09/09/25 at 06:15下午, Jakub Kicinski wrote: > Date: Tue, 9 Sep 2025 18:15:47 -0700 > From: Jakub Kicinski > To: 李克斯 > Cc: vkoul@kernel.org, davem@davemloft.net, wens@csie.org, > mripard@kernel.org, netdev@vger.kernel.org, dmaengine@vger.kernel.org, > linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org > Subject: Re: [PATCH] net: ethernet: sun4i-emac: free dma descriptor > > On Tue, 9 Sep 2025 14:36:42 +0800 李克斯 wrote: > > Thank you for the suggestion. I've reviewed the documentation, and > > setting the reuse flag while reusing descriptors might be a good > > optimization. I'll make the changes and run some tests. If everything > > works well, I'll submit a new patch. > > To be clear if you're saying the driver is buggy and can crash right > now we need to fix it first and then optimize it later, as separate > commits. So that LTS kernels can backport the fix. > > The questions I'm asking are because I don't understand whether the > upstream kernel is buggy and how exactly.. After carefully reviewing the documentation and how other drivers use dmaengine, I think that if the reuse flag is not set for the descriptor, manual release is unnecessary. Therefore, the current driver implementation does not contain a bug. This fix patch was a mistake. Thank you for your thorough review.