From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiner Kallweit Subject: Re: [PATCH] r8169: don't use MSI-X on RTL8106e Date: Tue, 21 Aug 2018 22:48:29 +0200 Message-ID: References: <20180820184438.GA154536@bhelgaas-glaptop.roam.corp.google.com> <9d7d960a-6c55-dc4b-7969-f5cf46bff0ce@gmail.com> <20180821.123108.89921430801253333.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: helgaas@kernel.org, jian-hong@endlessm.com, nic_swsd@realtek.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux@endlessm.com, linux-pci@vger.kernel.org, marc.zyngier@arm.com, tglx@linutronix.de, hch@lst.de To: David Miller Return-path: In-Reply-To: <20180821.123108.89921430801253333.davem@davemloft.net> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 21.08.2018 21:31, David Miller wrote: > From: Heiner Kallweit > Date: Mon, 20 Aug 2018 22:46:48 +0200 > >> I'm in contact with Realtek and according to them few chip versions >> seem to clear MSI-X table entries on resume from suspend. Checking >> with them how this could be fixed / worked around. >> Worst case we may have to disable MSI-X in general. > > I worry that if the chip does this, and somehow MSI-X is enabled and > an interrupt is generated, the chip will write to the cleared out > MSI-X address. This will either write garbage into memory or cause > a bus error and require PCI error recovery. > > It also looks like your test patch doesn't fix things for people who > have tested it. > The test patch was based on the first info from Realtek which made me think that the base address of the MSI-X table is cleared, what obviously is not the case. After some further tests it seems that the solution isn't as simple as storing the MSI-X table entries on suspend and restore them on resume. On my system (where MSI-X works fine) MSI-X table entries on resume are partially different from the ones on suspend. Unfortunately I don't have affected test hardware, currently I'm waiting for further feedback from Realtek. > Hmmm... >