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Date: Wed, 15 May 2024 15:55:47 -0500
From: Bjorn Helgaas <helgaas@kernel.org>
To: Rick Wertenbroek <rick.wertenbroek@gmail.com>
Cc: rick.wertenbroek@heig-vd.ch, dlemoal@kernel.org, stable@vger.kernel.org,
	Shawn Lin <shawn.lin@rock-chips.com>,
	Lorenzo Pieralisi <lpieralisi@kernel.org>,
	Krzysztof =?utf-8?Q?Wilczy=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: Re: [PATCH] PCI: rockchip-ep: Remove wrong mask on subsys_vendor_id
Message-ID: <20240515205547.GA2137633@bhelgaas>
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In-Reply-To: <20240403144508.489835-1-rick.wertenbroek@gmail.com>

On Wed, Apr 03, 2024 at 04:45:08PM +0200, Rick Wertenbroek wrote:
> 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

Applied to pci/controller/rockchip by Krzysztof, but his outgoing mail
queue got stuck.  I added Damien's Reviewed-by.  Trying to squeeze
into v6.9.

> ---
>  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
>