> >Hi Bjorn, > >On 2/28/2017 1:57 PM, Patel, Mayurkumar wrote: >>> I was trying to figure out when to use saved values vs. the values in >>> registers by looking at the enable_cnt. >>> enable_cnt is 0 during boot on my system. >> enable_cnt for the root port on my system is set to 1 for "root port" already without saving >> any ASPM related settings. >> >> > >What would be the best way to figure out when to save power-on values from >the registers? > So in my case, pci_enable_device() for root port is called from pcie_port_device_register() at the boot time which Is called from pcie_portdrv_probe() function which does not call pcie_aspm_init_link_state() but Increment's enable_cnt field. When the Endpoint get plugged in, pcie_aspm_init_link_state() is called from hotplug routine on "Root port" but due to enable_cnt is already incremented we do not set right policy and aspm gets disabled by aspm driver. Shall we introduce new atomic variable along with aspm_default in struct pci_dev and increment it in when called first time pcie_aspm_init_link_state() to save power-on values ( I have tested it locally, if you think could be good approach I can upload the diffs) because enable_cnt in pci_enable_device() can be triggered from multiple places at boot time so it might not be safe to use it? or adding pcie_aspm_init_link_state() in pcie_port_device_register() for ports before calling pci_enable_device() although I am not sure whether it's the right approach and that would work for all the devices! @Kaya/Bjorn: Do you have any other suggestions or Could you also please help by comment what would make sense? >-- >Sinan Kaya >Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. >Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. Intel Deutschland GmbH Registered Address: Am Campeon 10-12, 85579 Neubiberg, Germany Tel: +49 89 99 8853-0, www.intel.de Managing Directors: Christin Eisenschmid, Christian Lamprechter Chairperson of the Supervisory Board: Nicole Lau Registered Office: Munich Commercial Register: Amtsgericht Muenchen HRB 186928 -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
