In Resize BAR control register, bits[8:12] represents size of BAR. As per PCIe specification, below is encoded values in register bits to actual BAR size table:
Bits BAR size 0 1 MB 1 2 MB 2 4 MB 3 8 MB --
For 1 MB BAR size, BAR size bits should be set to 0 but incorrectly these bits are set to "1f". Latest megaraid_sas and mpt3sas adapters which support Resizable BAR with 1 MB BAR size fails to initialize during system resume from S3 sleep.
Fix: Correctly set BAR size bits to "0" for 1MB BAR size.
CC: stable@vger.kernel.org # v4.16+ Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939 Fixes: d3252ace0bc652a1a244455556b6a549f969bf99 ("PCI: Restore resized BAR state on resume") Signed-off-by: Sumit Saxena sumit.saxena@broadcom.com --- drivers/pci/pci.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 8abc843..b651f32 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1417,12 +1417,13 @@ static void pci_restore_rebar_state(struct pci_dev *pdev)
for (i = 0; i < nbars; i++, pos += 8) { struct resource *res; - int bar_idx, size; + int bar_idx, size, order;
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; res = pdev->resource + bar_idx; - size = order_base_2((resource_size(res) >> 20) | 1) - 1; + order = order_base_2((resource_size(res) >> 20) | 1); + size = order ? order - 1 : 0; ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);