]> git.proxmox.com Git - mirror_ubuntu-hirsute-kernel.git/commit
PCI: rockchip: Increase the Max Credit update interval
authorRajat Jain <rajatja@google.com>
Fri, 23 Sep 2016 00:50:42 +0000 (17:50 -0700)
committerBjorn Helgaas <bhelgaas@google.com>
Tue, 4 Oct 2016 17:16:03 +0000 (12:16 -0500)
commit277743ef616defc870d101f9cf9d3488aba1c1b6
tree441b59150934d2c7403bddc207168500c4eac1f9
parente77f847df54c6b01f4628dd352f4168db3082aa8
PCI: rockchip: Increase the Max Credit update interval

Increase the likelihood of link state to automatically go to L1 and save
some power.

The default credit update interval of 7.5 us results in the rootport
sending UpdateFC-P and UpdateFC-NP packets too often, thus resulting in the
link never going to L1, and always staying in L0/L0s.  The value 24 us was
chosen after some experiments and peeking over the PCIe bus to see that we
do enter L1 substate when there is not enough traffic on the PCIe bus.

Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com>
drivers/pci/host/pcie-rockchip.c