Messages in this thread |  | | From | David Laight <> | Subject | RE: [RESEND PATCH] arm: Enlarge IO_SPACE_LIMIT needed for some SoC | Date | Sun, 9 May 2021 16:54:51 +0000 |
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... > Well, an obvious question would be: do you really need that much IO > space? PCs have got away with 64K of IO space without having a problem > for years, so 64K per bus should be fine. If you have 3 buses, that > should be 3 * 64K or 192K.
Not only that, but most modern PCI (even) cards don't require IO space. Or does this include memory space - which can be much bigger.
I have cut one of our FPGA PCIe slaves down from two 8MB BARs to two 1MB ones, with the extra small BARs (eg for MSI-X) the bridge would have allocated 32MB, now 4MB. Fortunately that card only needs to work on x86-64.
David
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