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| author | Niklas Cassel <cassel@kernel.org> | 2024-03-07 12:15:20 +0100 |
|---|---|---|
| committer | Krzysztof Wilczyński <kwilczynski@kernel.org> | 2024-03-10 18:51:01 +0000 |
| commit | 72e34b8593e08a0ee759b7a038e0b178418ea6f8 (patch) | |
| tree | 5dc48dda0d51f41257541b4c1eb8ab4556884736 | |
| parent | f3a296405b6e65fe478144c2f85602dc5668700c (diff) | |
PCI: dwc: endpoint: Fix advertised resizable BAR size
The commit message in commit fc9a77040b04 ("PCI: designware-ep: Configure
Resizable BAR cap to advertise the smallest size") claims that it modifies
the Resizable BAR capability to only advertise support for 1 MB size BARs.
However, the commit writes all zeroes to PCI_REBAR_CAP (the register which
contains the possible BAR sizes that a BAR be resized to).
According to the spec, it is illegal to not have a bit set in
PCI_REBAR_CAP, and 1 MB is the smallest size allowed.
Set bit 4 in PCI_REBAR_CAP, so that we actually advertise support for a
1 MB BAR size.
Before:
Capabilities: [2e8 v1] Physical Resizable BAR
BAR 0: current size: 1MB
BAR 1: current size: 1MB
BAR 2: current size: 1MB
BAR 3: current size: 1MB
BAR 4: current size: 1MB
BAR 5: current size: 1MB
After:
Capabilities: [2e8 v1] Physical Resizable BAR
BAR 0: current size: 1MB, supported: 1MB
BAR 1: current size: 1MB, supported: 1MB
BAR 2: current size: 1MB, supported: 1MB
BAR 3: current size: 1MB, supported: 1MB
BAR 4: current size: 1MB, supported: 1MB
BAR 5: current size: 1MB, supported: 1MB
Fixes: fc9a77040b04 ("PCI: designware-ep: Configure Resizable BAR cap to advertise the smallest size")
Link: https://lore.kernel.org/linux-pci/20240307111520.3303774-1-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: <stable@vger.kernel.org> # 5.2
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware-ep.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c index 5befed2dc02b..389daebc4316 100644 --- a/drivers/pci/controller/dwc/pcie-designware-ep.c +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c @@ -627,8 +627,13 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep) nbars = (reg & PCI_REBAR_CTRL_NBAR_MASK) >> PCI_REBAR_CTRL_NBAR_SHIFT; + /* + * PCIe r6.0, sec 7.8.6.2 require us to support at least one + * size in the range from 1 MB to 512 GB. Advertise support + * for 1 MB BAR size only. + */ for (i = 0; i < nbars; i++, offset += PCI_REBAR_CTRL) - dw_pcie_writel_dbi(pci, offset + PCI_REBAR_CAP, 0x0); + dw_pcie_writel_dbi(pci, offset + PCI_REBAR_CAP, BIT(4)); } /* |