Re: [PATCH 18/29] ixgbe/base: update swfw semaphore function

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 5/6/2016 7:07 AM, Beilei Xing wrote:
> For X540 and forward it is possible if a system reset occur at the
> right time to leave the SWFW semaphore high. This new function will
> attempt to grab and release the semaphore. If the grab times out it
> will still release the semaphore placing it in a known good state.
> The idea is to call this when you know no one should be holding the
> semaphore (i.e. probe time)
> This patch alse fixes possible race issue between ports when issuing
> host interface command by acquiring/releasing the management host
> interface semaphore in ixgbe_host_interface_command.
> 
> Signed-off-by: Beilei Xing <beilei.xing@intel.com>
> ---
Does it make sense to separate this patch into two.

...

> +/**
> + *  ixgbe_init_swfw_semaphore - Clean up SWFW semaphore
> + *  @hw: pointer to hardware structure
> + *
> + *  Attempts to acquire the SWFW semaphore through SW_FW_SYNC register.
> + *  Regardless of whether is succeeds or not it then release the semaphore.
> + *  This is function is called to recover from catastrophic failures that
> + *  may have left the semaphore locked.
> + **/
> +void ixgbe_init_swfw_semaphore(struct ixgbe_hw *hw)
> +{
> +	if (hw->mac.ops.init_swfw_sync)
> +		hw->mac.ops.init_swfw_sync(hw);
> +}
One add ixgbe_init_swfw_semaphore related code (init_swfw_sync,
ixgbe_init_swfw_sync_X540)

...

> @@ -4390,6 +4392,12 @@ s32 ixgbe_host_interface_command(struct ixgbe_hw *hw, u32 *buffer,
>  		DEBUGOUT1("Buffer length failure buffersize=%d.\n", length);
>  		return IXGBE_ERR_HOST_INTERFACE_COMMAND;
>  	}
> +	/* Take management host interface semaphore */
> +	status = hw->mac.ops.acquire_swfw_sync(hw, IXGBE_GSSR_SW_MNG_SM);
> +
> +	if (status)
> +		return status;
> +
Second is fix in ixgbe_host_interface_command, they are unrelated as far
as I can see.

>  	/* Set bit 9 of FWSTS clearing FW reset indication */
>  	fwsts = IXGBE_READ_REG(hw, IXGBE_FWSTS);
>  	IXGBE_WRITE_REG(hw, IXGBE_FWSTS, fwsts | IXGBE_FWSTS_FWRI);
...