Re: [PATCH v1 09/12] net/ice/base: improve global config lock behavior

[Bruce Richardson <bruce.richardson@intel.com>]

On Tue, Sep 02, 2025 at 06:26:59PM +0100, Anatoly Burakov wrote:
> From: Jacob Keller <jacob.e.keller@intel.com>
> 
> The ice_cfg_tx_topo function attempts to apply Tx scheduler topology
> configuration based on NVM parameters, selecting either a 5 or 9 layer
> topology.
> 
> As part of this flow, the driver acquires the "Global Configuration
> Lock", which is a hardware resource associated with programming the DDP
> package to the device. This "lock" is implemented by firmware as a way to
> guarantee that only one PF can program the DDP for a device. Unlike a
> traditional lock, once a PF has acquired this lock, no other PF will be
> able to acquire it again (including that PF) until a core reset of the
> device. Future requests to acquire the lock report that global
> configuration has already completed.
> 
> The following flow is used to program the Tx topology:
> 
>  * Read the DDP package for scheduler configuration data
>  * Acquire the global configuration lock
>  * Program Tx scheduler topology according to DDP package data
>  * Trigger a core reset which clears the global configuration lock
> 
> This is followed by the flow for programming the DDP package:
> 
>  * Acquire the global configuration lock (again)
>  * Download the DDP package to the device
>  * Release the global configuration lock.
> 
> However, if configuration of the Tx topology fails, (i.e.
> ice_get_set_tx_topo() returns an error code), the driver exits
> ice_cfg_tx_topo() immediately, and fails to trigger core reset.
> 
> While the global configuration lock is held, the firmware rejects most
> AdminQ commands, as it is waiting for the DDP package download (or Tx
> scheduler topology programming) to occur.
> 
> The current driver flows assume that the global configuration lock has
> been reset after programming the Tx topology. Thus, the same PF attempts
> to acquire the global lock again, and fails. This results in the driver
> reporting "an unknown error occurred when loading the DDP package". It
> then attempts to enter safe mode, but ultimately fails to finish
> ice_probe() since nearly all AdminQ command report error codes, and the
> driver stops loading the device at some point during its initialization.
> 
> We cannot simply release the global lock after a failed call to
> ice_get_set_tx_topo(). Releasing the lock indicates to firmware that
> global configuration (downloading of the DDP) has completed. Future
> attempts by this or other PFs to load the DDP will fail with a report
> that the DDP package has already been downloaded. Then, PFs will enter
> safe mode as they realize that the package on the device does not meet
> the minimum version requirement to load. The reported error messages are
> confusing, as they indicate the version of the default "safe mode"
> package in the NVM, rather than the version of the DDP package loaded
> from the filesystem.
> 
> Instead, we need to trigger core reset to clear global configuration.
> This is the lowest level of hardware reset which clears the global
> configuration lock and related state. It also clears any already
> downloaded DDP. Crucially, it does *not* clear the Tx scheduler topology
> configuration.
> 
> Refactor ice_cfg_tx_topo() to always trigger a core reset after acquiring
> the global lock, regardless of success or failure of the topology
> configuration.
> 
> We need to re-initialize the HW structure when we trigger the core reset.
> Previously, this was the responsibility of the core driver to cleanup
> after the core reset. Instead, make it the responsibility of this
> function. This avoids needless re-initialization for the cases where no
> reset occurred.
> 
> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> ---
>  drivers/net/intel/ice/base/ice_ddp.c | 34 ++++++++++++++++++----------
>  1 file changed, 22 insertions(+), 12 deletions(-)
> 

Acked-by: Bruce Richardson <bruce.richardson@intel.com>

See one comment inline below.


> diff --git a/drivers/net/intel/ice/base/ice_ddp.c b/drivers/net/intel/ice/base/ice_ddp.c
> index 850c722a3f..68e75be4d2 100644
> --- a/drivers/net/intel/ice/base/ice_ddp.c
> +++ b/drivers/net/intel/ice/base/ice_ddp.c
> @@ -2370,7 +2370,7 @@ int ice_cfg_tx_topo(struct ice_hw *hw, u8 *buf, u32 len)
>  	struct ice_buf_hdr *section;
>  	struct ice_pkg_hdr *pkg_hdr;
>  	enum ice_ddp_state state;
> -	u16 i, size = 0, offset;
> +	u16 size = 0, offset;
>  	u32 reg = 0;
>  	int status;
>  	u8 flags;
> @@ -2457,25 +2457,35 @@ int ice_cfg_tx_topo(struct ice_hw *hw, u8 *buf, u32 len)
>  	/* check reset was triggered already or not */
>  	reg = rd32(hw, GLGEN_RSTAT);
>  	if (reg & GLGEN_RSTAT_DEVSTATE_M) {
> -		/* Reset is in progress, re-init the hw again */
>  		ice_debug(hw, ICE_DBG_INIT, "Reset is in progress. layer topology might be applied already\n");
>  		ice_check_reset(hw);
> -		return 0;
> +		/* Reset is in progress, re-init the hw again */
> +		goto reinit_hw;
>  	}
>  
>  	/* set new topology */
>  	status = ice_get_set_tx_topo(hw, new_topo, size, NULL, NULL, true);
>  	if (status) {
> -		ice_debug(hw, ICE_DBG_INIT, "Set tx topology is failed\n");
> -		return status;
> +		ice_debug(hw, ICE_DBG_INIT, "Failed setting Tx topology, status %d\n",
> +			  status);
> +		status = ICE_ERR_CFG;
>  	}
>  
> -	/* new topology is updated, delay 1 second before issuing the CORRER */
> -	for (i = 0; i < 10; i++)
> -		ice_msec_delay(100, true);
> +	/* Even if Tx topology config failed, we need to CORE reset here to
> +	 * clear the global configuration lock. Delay 1 second to allow
> +	 * hardware to settle then issue a CORER
> +	 */
> +	ice_msec_delay(1000, true);
>  	ice_reset(hw, ICE_RESET_CORER);
> -	/* CORER will clear the global lock, so no explicit call
> -	 * required for release
> -	 */
> -	return 0;
> +	ice_check_reset(hw);
> +
> +reinit_hw:
> +	/* Since we triggered a CORER, re-initialize hardware */
> +	ice_deinit_hw(hw);
> +	if (ice_init_hw(hw)) {
> +		ice_debug(hw, ICE_DBG_INIT, "Failed to re-init hardware after setting Tx topology\n");
> +		return ICE_ERR_RESET_FAILED;
> +	}
> +
> +	return status;
>  }

There is a similer deinit + init combo in ice_init_pkg in the same file,
which is the only use of this function (in DPDK anyway). Therefore, I
believe that that code can be removed now that the reinit is handled by the
cfg_tx_topo() function.