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Myron Stowe authored
commit 06cf35f9 upstream. Some AMD CS553x devices have read-only BARs because of a firmware or hardware defect. There's a workaround in quirk_cs5536_vsa(), but it no longer works after 36e81648 ("PCI: Restore detection of read-only BARs"). Prior to 36e81648, we filled in res->start; afterwards we leave it zeroed out. The quirk only updated the size, so the driver tried to use a region starting at zero, which didn't work. Expand quirk_cs5536_vsa() to read the base addresses from the BARs and hard-code the sizes. On Nix's system BAR 2's read-only value is 0x6200. Prior to 36e81648, we interpret that as a 512-byte BAR based on the lowest-order bit set. Per datasheet sec 5.6.1, that BAR (MFGPT) requires only 64 bytes; use that to avoid clearing any address bits if a platform uses only 64-byte alignment. [bhelgaas: changelog, reduce BAR 2 size to 64] Fixes: 36e81648 ("PCI: Restore detection of read-only BARs") Link: https://bugzilla.kernel.org/show_bug.cgi?id=85991#c4 Link: http://support.amd.com/TechDocs/31506_cs5535_databook.pdf Link: http://support.amd.com/TechDocs/33238G_cs5536_db.pdfReported-and-tested-by: Nix <nix@esperi.org.uk> Signed-off-by: Myron Stowe <myron.stowe@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
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