On 23/10/17 12:31, Pavel Machek wrote:

Hi!

quoted

quoted

quoted

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.

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