Re: [PATCH 3/5] thunderbolt: Verify Router Ready bit is set after router enumeration

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Tue, Jan 27, 2026 at 12:06:04AM +0200, Gil Fine wrote:
> The USB4 Connection Manager guide specifies that after enumerating a
> router, the Connection Manager shall verify that the Router Ready bit
> (ROUTER_CS_6.RR) has been set to ensure hardware configuration has completed.
> Currently, this step is missing from the enumeration sequence.
> 
> Add this check to follow the Connection Manager guide more closely.
> 
> Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
> ---
>  drivers/thunderbolt/switch.c  | 5 +++++
>  drivers/thunderbolt/tb_regs.h | 1 +
>  2 files changed, 6 insertions(+)
> 
> diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
> index e7faa203b782..11e8c1dd3090 100644
> --- a/drivers/thunderbolt/switch.c
> +++ b/drivers/thunderbolt/switch.c
> @@ -2641,6 +2641,11 @@ int tb_switch_configure(struct tb_switch *sw)
>  			return ret;
>  
>  		ret = usb4_switch_setup(sw);
> +		if (ret)
> +			return ret;
> +
> +		ret = tb_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_RR,
> +					     ROUTER_CS_6_RR, 500);

Can you move this inside usb4_switch_setup()?


>  	} else {
>  		if (sw->config.vendor_id != PCI_VENDOR_ID_INTEL)
>  			tb_sw_warn(sw, "unknown switch vendor id %#x\n",
> diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
> index 71bed02a6974..7e65bc9bcb12 100644
> --- a/drivers/thunderbolt/tb_regs.h
> +++ b/drivers/thunderbolt/tb_regs.h
> @@ -216,6 +216,7 @@ struct tb_regs_switch_header {
>  #define ROUTER_CS_6_WOPS			BIT(2)
>  #define ROUTER_CS_6_WOUS			BIT(3)
>  #define ROUTER_CS_6_HCI				BIT(18)
> +#define ROUTER_CS_6_RR				BIT(24)
>  #define ROUTER_CS_6_CR				BIT(25)
>  #define ROUTER_CS_7				0x07
>  #define ROUTER_CS_9				0x09
> -- 
> 2.43.0