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From: Rick Wertenbroek <rick.wertenbroek@gmail.com>
To: rick.wertenbroek@heig-vd.ch
Cc: dlemoal@kernel.org,
	Rick Wertenbroek <rick.wertenbroek@gmail.com>,
	stable@vger.kernel.org,
	Shawn Lin <shawn.lin@rock-chips.com>,
	Lorenzo Pieralisi <lpieralisi@kernel.org>,
	=?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
	Rob Herring <robh@kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Heiko Stuebner <heiko@sntech.de>,
	linux-pci@vger.kernel.org,
	linux-rockchip@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] PCI: rockchip-ep: Remove wrong mask on subsys_vendor_id
Date: Wed,  3 Apr 2024 16:45:08 +0200
Message-Id: <20240403144508.489835-1-rick.wertenbroek@gmail.com>
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Remove wrong mask on subsys_vendor_id. Both the Vendor ID and Subsystem
Vendor ID are u16 variables and are written to a u32 register of the
controller. The Subsystem Vendor ID was always 0 because the u16 value
was masked incorrectly with GENMASK(31,16) resulting in all lower 16
bits being set to 0 prior to the shift.

Remove both masks as they are unnecessary and set the register correctly
i.e., the lower 16-bits are the Vendor ID and the upper 16-bits are the
Subsystem Vendor ID.

This is documented in the RK3399 TRM section 17.6.7.1.17

Fixes: cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip PCIe controller")
Signed-off-by: Rick Wertenbroek <rick.wertenbroek@gmail.com>
Cc: stable@vger.kernel.org
---
 drivers/pci/controller/pcie-rockchip-ep.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index c9046e97a1d2..37d4bcb8bd5b 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -98,10 +98,9 @@ static int rockchip_pcie_ep_write_header(struct pci_epc *epc, u8 fn, u8 vfn,
 
 	/* All functions share the same vendor ID with function 0 */
 	if (fn == 0) {
-		u32 vid_regs = (hdr->vendorid & GENMASK(15, 0)) |
-			       (hdr->subsys_vendor_id & GENMASK(31, 16)) << 16;
-
-		rockchip_pcie_write(rockchip, vid_regs,
+		rockchip_pcie_write(rockchip,
+				    hdr->vendorid |
+				    hdr->subsys_vendor_id << 16,
 				    PCIE_CORE_CONFIG_VENDOR);
 	}
 
-- 
2.25.1