Re: [PATCH] iwlwifi: don't panic in error path on non-msix systems

[Luca Coelho]

On Wed, 2019-04-17 at 12:11 +0200, Michal Hocko wrote:
> Hi,
> which tree is this supposed to be applied on? It doesn't do apply on
> top
> of v5.1-rc4-3-gfd008d1a7a20. iwl_trans_pcie_sync_nmi doesn't exist in
> drivers/net/wireless/intel/iwlwifi/pcie/trans.c. iwl_trans_sync_nmi
> looks pretty similar. My patch massaging ended up with this. Please
> double check. It compiles and even boots.

Ah, sorry, I didn't mention that that patch was supposed to apply on
top of wireless-drivers-next, which is on its way to v5.2.  We have
other patches touching this function there, thus the conflict.

> diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
> b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
> index fe8269d023de..1f3969e2bcac 100644
> --- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
> +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
> @@ -3639,20 +3639,27 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct
> pci_dev *pdev,
>  
>  void iwl_trans_sync_nmi(struct iwl_trans *trans)
>  {
> +	struct iwl_trans_pcie *trans_pcie =
> IWL_TRANS_GET_PCIE_TRANS(trans);
>  	unsigned long timeout = jiffies + IWL_TRANS_NMI_TIMEOUT;
> +	u32 inta_addr, sw_err_bit;
> +
> +	if (trans_pcie->msix_enabled) {
> +		inta_addr = CSR_MSIX_HW_INT_CAUSES_AD;
> +		sw_err_bit = MSIX_HW_INT_CAUSES_REG_SW_ERR;
> +	} else {
> +		inta_addr = CSR_INT;
> +		sw_err_bit = CSR_INT_BIT_SW_ERR;
> +	}
>  
>  	iwl_disable_interrupts(trans);
>  	iwl_force_nmi(trans);
>  	while (time_after(timeout, jiffies)) {
> -		u32 inta_hw = iwl_read32(trans,
> -					 CSR_MSIX_HW_INT_CAUSES_AD);
> +		u32 inta_hw = iwl_read32(trans, inta_addr);
>  
>  		/* Error detected by uCode */
> -		if (inta_hw & MSIX_HW_INT_CAUSES_REG_SW_ERR) {
> +		if (inta_hw & sw_err_bit) {
>  			/* Clear causes register */
> -			iwl_write32(trans, CSR_MSIX_HW_INT_CAUSES_AD,
> -				    inta_hw &
> -				    MSIX_HW_INT_CAUSES_REG_SW_ERR);
> +			iwl_write32(trans, inta_addr, inta_hw &
> sw_err_bit);
>  			break;
>  		}

This looks good! So it fixed the problem you were having now?


--
Cheers,
Luca.