[PATCH] PCI : check if type 0 devices have all BARs of size zero

From: Wasim Khan
Date: Fri Feb 12 2021 - 05:10:28 EST


From: Wasim Khan <wasim.khan@xxxxxxx>

Log a message if all BARs of type 0 devices are of
size zero. This can help detecting type 0 devices
not reporting BAR size correctly.

Signed-off-by: Wasim Khan <wasim.khan@xxxxxxx>
---
drivers/pci/probe.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 953f15abc850..6438d6d56777 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -321,6 +321,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
{
unsigned int pos, reg;
+ bool found = false;

if (dev->non_compliant_bars)
return;
@@ -333,8 +334,12 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
struct resource *res = &dev->resource[pos];
reg = PCI_BASE_ADDRESS_0 + (pos << 2);
pos += __pci_read_base(dev, pci_bar_unknown, res, reg);
+ found |= res->flags ? 1 : 0;
}

+ if (!dev->hdr_type && !found)
+ pci_info(dev, "BAR size is 0 for BAR[0..%d]\n", howmany - 1);
+
if (rom) {
struct resource *res = &dev->resource[PCI_ROM_RESOURCE];
dev->rom_base_reg = rom;
--
2.25.1