Aw: Re: Re: [PATCH 09/13] PCI: mediatek: Advertise lack of MSI handling

From: Frank Wunderlich <frank-w@public-files.de>
To: Marc Zyngier <maz@kernel.org>, Chuanjia Liu <chuanjia.liu@mediatek.com>
Cc: linux-hyperv@vger.kernel.org, linux-pci@vger.kernel.org,
	Bjorn Helgaas <bhelgaas@google.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Will Deacon <will@kernel.org>,
	Marek Vasut <marek.vasut+renesas@gmail.com>,
	Rob Herring <robh@kernel.org>, Wei Liu <wei.liu@kernel.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Michal Simek <michal.simek@xilinx.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Thierry Reding <treding@nvidia.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Ryder Lee <ryder.lee@mediatek.com>,
	linux-mediatek@lists.infradead.org,
	Paul Walmsley <paul.walmsley@sifive.com>,
	linux-tegra@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	linux-arm-kernel@lists.infradead.org,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org
Subject: Aw: Re:  Re:  [PATCH 09/13] PCI: mediatek: Advertise lack of MSI handling
Date: Mon, 1 Mar 2021 15:06:38 +0100	[thread overview]
Message-ID: <trinity-e6593a34-3e03-4154-a03c-f3aed01e33bf-1614607598428@3c-app-gmx-bap67> (raw)
In-Reply-To: <5afd1d656299d87c43bdf31b8ced2d5f@kernel.org>

> Gesendet: Montag, 01. März 2021 um 14:31 Uhr
> Von: "Marc Zyngier" <maz@kernel.org>
>
> Frank,
> 
> >> > i guess it's a bug in ath10k driver or my r64 board (it is a v1.1
> >> > which has missing capacitors on tx lines).
> >> 
> >> No, this definitely looks like a bug in the MTK PCIe driver,
> >> where the mutex is either not properly initialised, corrupted,
> >> or the wrong pointer is passed.
> > 
> > but why does it happen only with the ath10k-card and not the mt7612 in
> > same slot?
> 
> Does mt7612 use MSI? What we have here is a bogus mutex in the
> MTK PCIe driver, and the only way not to get there would be
> to avoid using MSIs.

i guess this card/its driver does not use MSI. Did not found anything in "datasheet" [1] or driver [2] about msi

> > 
> >> This r64 machine is supposed to have working MSIs, right?
> > 
> > imho mt7622 have working MSI
> > 
> >> Do you get the same issue without this series?
> > 
> > tested 5.11.0 [1] without this series (but with your/thomas' patch
> > from discussion about my old patch) and got same trace. so this series
> > does not break anything here.
> 
> Can you retest without any additional patch on top of 5.11?
> These two patches only affect platforms that do *not* have MSIs at all.

i can revert these 2, but still need patches for mt7622 pcie-support [3]...btw. i see that i miss these in 5.11-main...do not see traceback with them (have firmware not installed...)

root@bpi-r64:~# dmesg | grep ath                                                
[    6.450765] ath10k_pci 0000:01:00.0: assign IRQ: got 146                     
[    6.661752] ath10k_pci 0000:01:00.0: enabling device (0000 -> 0002)          
[    6.697811] ath10k_pci 0000:01:00.0: enabling bus mastering                  
[    6.721293] ath10k_pci 0000:01:00.0: pci irq msi oper_irq_mode 2 irq_mode 0 r
eset_mode 0                                                                     
[    6.921030] ath10k_pci 0000:01:00.0: Failed to find firmware-N.bin (N between
 2 and 6) from ath10k/QCA988X/hw2.0: -2                                         
[    6.931698] ath10k_pci 0000:01:00.0: could not fetch firmware files (-2)     
[    6.940417] ath10k_pci 0000:01:00.0: could not probe fw (-2)

so traceback was caused by missing changes in mtk pcie-driver not yet upstream, added Chuanjia Liu

> > 
> >> > Tried with an mt7612e, this seems to work without any errors.
> >> >
> >> > so for mt7622/mt7623
> >> >
> >> > Tested-by: Frank Wunderlich <frank-w@public-files.de>
> >> 
> >> We definitely need to understand the above.
> > 
> > there is a hardware-bug which may cause this...afair i saw this with
> > the card in r64 with earlier Kernel-versions where other cards work
> > (like the mt7612e).
> 
> I don't think a HW bug affecting PCI would cause what we are seeing
> here, unless it results in memory corruption.

[1] https://www.asiarf.com/shop/wifi-wlan/wifi_mini_pcie/ws2433-wifi-11ac-mini-pcie-module-manufacturer/
[2] grep -Rni 'msi' drivers/net/wireless/mediatek/mt76/mt76x2/
[3] https://patchwork.kernel.org/project/linux-mediatek/list/?series=372885

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