Re: [PATCH v6 08/14] PCI: cadence: Fix updating Vendor ID and Subsystem Vendor ID register
From: Rob Herring <robh@kernel.org>
Date: 2020-07-09 21:46:00
Also in:
linux-devicetree, linux-omap, linux-pci, lkml
On Wed, Jul 08, 2020 at 03:00:12PM +0530, Kishon Vijay Abraham I wrote:
quoted hunk ↗ jump to hunk
Commit 1b79c5284439 ("PCI: cadence: Add host driver for Cadence PCIe controller") in order to update Vendor ID, directly wrote to PCI_VENDOR_ID register. However PCI_VENDOR_ID in root port configuration space is read-only register and writing to it will have no effect. Use local management register to configure Vendor ID and Subsystem Vendor ID. Fixes: 1b79c5284439 ("PCI: cadence: Add host driver for Cadence PCIe controller") Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Kishon Vijay Abraham I <redacted> --- drivers/pci/controller/cadence/pcie-cadence-host.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c index 10127ea71b83..8935f7a37e5a 100644 --- a/drivers/pci/controller/cadence/pcie-cadence-host.c +++ b/drivers/pci/controller/cadence/pcie-cadence-host.c@@ -82,6 +82,7 @@ static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc) { struct cdns_pcie *pcie = &rc->pcie; u32 value, ctrl; + u32 id; /* * Set the root complex BAR configuration register:@@ -101,8 +102,12 @@ static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc) cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value); /* Set root port configuration space */ - if (rc->vendor_id != 0xffff) - cdns_pcie_rp_writew(pcie, PCI_VENDOR_ID, rc->vendor_id);
If this is read-only, then...
+ if (rc->vendor_id != 0xffff) {
+ id = CDNS_PCIE_LM_ID_VENDOR(rc->vendor_id) |
+ CDNS_PCIE_LM_ID_SUBSYS(rc->vendor_id);
+ cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, id);
+ }
+
if (rc->device_id != 0xffff)
cdns_pcie_rp_writew(pcie, PCI_DEVICE_ID, rc->device_id);...isn't this read-only too?
-- 2.17.1
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