Re: 4.14-rc2 on thinkpad x220: out of memory when inserting mmc card

[Adrian Hunter]

On 23/10/17 12:31, Pavel Machek wrote:
> Hi!
> 
>>>> Did you use bounce buffers? Those were improving performance on
>>>> some laptops with TI or Ricoh host controllers and nothing else was
>>>> ever really using it (as can be seen from the commit).
>>>
>>> Thinkpad X220... how do I tell if I was using them? I believe so,
>>> because I uncovered bug in them before.
>>
>> You are certainly using bounce buffers.  What does lspci -knn show?
> 
> Here is the output:
> 									Pavel
> 
> 00:00.0 Host bridge [0600]: Intel Corporation 2nd Generation Core Processor Family DRAM Controller [8086:0104] (rev 09)
> 	Subsystem: Lenovo Device [17aa:21da]
> 00:02.0 VGA compatible controller [0300]: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0126] (rev 09)
> 	Subsystem: Lenovo Device [17aa:21da]
> 	Kernel driver in use: i915
> 00:16.0 Communication controller [0780]: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 [8086:1c3a] (rev 04)
> 	Subsystem: Lenovo Device [17aa:21da]
> 00:19.0 Ethernet controller [0200]: Intel Corporation 82579LM Gigabit Network Connection [8086:1502] (rev 04)
> 	Subsystem: Lenovo Device [17aa:21ce]
> 	Kernel driver in use: e1000e
> 00:1a.0 USB controller [0c03]: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 [8086:1c2d] (rev 04)
> 	Subsystem: Lenovo Device [17aa:21da]
> 	Kernel driver in use: ehci-pci
> 00:1b.0 Audio device [0403]: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller [8086:1c20] (rev 04)
> 	Subsystem: Lenovo Device [17aa:21da]
> 	Kernel driver in use: snd_hda_intel
> 00:1c.0 PCI bridge [0604]: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 [8086:1c10] (rev b4)
> 	Kernel driver in use: pcieport
> 00:1c.1 PCI bridge [0604]: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 2 [8086:1c12] (rev b4)
> 	Kernel driver in use: pcieport
> 00:1c.3 PCI bridge [0604]: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 4 [8086:1c16] (rev b4)
> 	Kernel driver in use: pcieport
> 00:1c.4 PCI bridge [0604]: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 5 [8086:1c18] (rev b4)
> 	Kernel driver in use: pcieport
> 00:1d.0 USB controller [0c03]: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 [8086:1c26] (rev 04)
> 	Subsystem: Lenovo Device [17aa:21da]
> 	Kernel driver in use: ehci-pci
> 00:1f.0 ISA bridge [0601]: Intel Corporation QM67 Express Chipset Family LPC Controller [8086:1c4f] (rev 04)
> 	Subsystem: Lenovo Device [17aa:21da]
> 00:1f.2 SATA controller [0106]: Intel Corporation 6 Series/C200 Series Chipset Family 6 port SATA AHCI Controller [8086:1c03] (rev 04)
> 	Subsystem: Lenovo Device [17aa:21da]
> 	Kernel driver in use: ahci
> 00:1f.3 SMBus [0c05]: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller [8086:1c22] (rev 04)
> 	Subsystem: Lenovo Device [17aa:21da]
> 03:00.0 Network controller [0280]: Intel Corporation Centrino Wireless-N 1000 [Condor Peak] [8086:0084]
> 	Subsystem: Intel Corporation Centrino Wireless-N 1000 BGN [8086:1315]
> 	Kernel driver in use: iwlwifi
> 0d:00.0 System peripheral [0880]: Ricoh Co Ltd PCIe SDXC/MMC Host Controller [1180:e823] (rev 07)
> 	Subsystem: Lenovo Device [17aa:21da]
> 	Kernel driver in use: sdhci-pci

Yes, the code for Ricoh in sdhci-pci specifies only SDMA which means no
scatter-gather.  That might benefit from bounce buffers, but it seems like
the memory allocation was silently failing anyway if a card was inserted
after memory has fragmented.