Messages in this thread |  | | From | Nicholas Johnson <> | Subject | Re: [PATCH v1 4/4] PCI: Allow extend_bridge_window() to shrink resource if necessary | Date | Wed, 15 Jan 2020 14:51:02 +0000 |
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On Mon, Jan 13, 2020 at 06:21:50PM +0200, Mika Westerberg wrote: > On Wed, Jan 08, 2020 at 01:36:04AM +0000, Nicholas Johnson wrote: > > > Where's the patch that changes the caller so "new_size" may be smaller > > > than "size"? I guess it must be "[3/3] PCI: Consider alignment of > > > hot-added bridges ..." because that's the only one that makes a > > > non-trivial change, right? > > > > As above, there was always a possibility of the new_size being smaller. > > For some reason, 1M is assigned to bridges, even if nothing is below > > them (for example, unused non hotplug bridges in a Thunderbolt dock). It > > may be an edge case if we are low on space, but theoretically it can > > happen. > > > > Also, when writing this, Mika was not interested in using hpmemsize, > > which, when used, will cause new_size to be smaller than the current > > size (actual size and add_size combined). > > Just a small correction here about my motivation. So I'm testing on a > hardware where the BIOS assigns initial resources to the root/downstream > ports which is the majority of Thunderbolt capable PC systems nowadays. > Therefore the user does not need to pass any additional command line > parameters to get the ports working properly. > > However, I'm of course interested in getting Linux PCI resource > management as good as possible regardless whether the firmware/BIOS > assigns them or not ;-) Sorry, I was not meant to say you were not interested in getting it as good as possible. At the time, you had a goal to achieve (which you did) and at that point in time, it would not have been feasible to use pci=hpmemsize or similar before my patches were applied:
c13704f5685d ("PCI: Avoid double hpmemsize MMIO window assignment") d7b8a217521c ("PCI: Add "pci=hpmmiosize" and "pci=hpmmioprefsize" parameters")
What I was trying to say was not that you were not interested, but more that it was not a primary motivation for you at the time. Does this sound more accurate? Poor wording on my behalf.
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