On Mon, Nov 26, 2018 at 11:37:20PM +0100, Rafael J. Wysocki wrote: > On Monday, November 26, 2018 7:03:58 PM CET Rafael J. Wysocki wrote: > > Hi Bjorn, > > > > The SD card reader in my Acer Aspire S5 doesn't work with 4.20-rc. > > > > Here's what lspci -v says about it (in a bad kernel): > > > > 02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5209 PCI Express Card Reader > > (rev 01) > > Subsystem: Acer Incorporated [ALI] Device 0704 > > Flags: bus master, fast devsel, latency 0, IRQ 35 > > Memory at d9001000 (32-bit, non-prefetchable) [size=4K] > > Capabilities: [40] Power Management version 3 > > Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+ > > Capabilities: [70] Express Endpoint, MSI 00 > > Capabilities: [100] Advanced Error Reporting > > Capabilities: [140] Device Serial Number 00-00-00-01-00-4c-e0-00 > > Kernel driver in use: rtsx_pci > > Kernel modules: rtsx_pci Thanks a lot for bisecting this! With a good kernel (v4.19 or v4.20-rc with 17c91487364f reverted), would you mind collecting "lspci -vv" output, the dmesg log with "pci=earlydump", and the FADT dump? I'm interested in the initial state of the device at handoff from BIOS, and what Linux changes even when aspm_disabled is set. If we can't figure out a way to fix both this issue and the one fixed by 17c91487364f, I guess the fallback will be to revert 17c91487364f since it's better to allow a system that was previously broken to remain broken than it is to break a system that previously worked. But obviously I hope we can figure out a solution that fixes both cases. > > When it doesn't work, it doesn't generate any interrupts on device insertion > > and removal and this seems to be reproducible 100% of the time. > > So reverting 17c91487364f (PCI/ASPM: Do not initialize link state when > aspm_disabled is set) on top of 4.20-rc4 makes the problem go away. > > I guess that the device in question needs pcie_aspm_cap_init() to be > called for it even though the FADT says "NO_ASPM".
