Re: [PATCH net v1] net: stmmac: xgmac: Disable FPE MMC interrupts

[Wojciech Drewek]

On 23.11.2023 11:24, Furong Xu wrote:
> On Thu, 23 Nov 2023 11:17:17 +0100
> Wojciech Drewek <wojciech.drewek@xxxxxxxxx> wrote:
> 
>> On 23.11.2023 10:35, Furong Xu wrote:
>>> Commit aeb18dd07692 ("net: stmmac: xgmac: Disable MMC interrupts
>>> by default") leaves the FPE(Frame Preemption) MMC interrupts enabled.
>>> Now we disable FPE TX and RX interrupts too.  
>>
>> Hi,
>> Thanks for the patch, one question:
>> Why do we have to disable them?
>>
> 
> The original commit aeb18dd07692 by Jose Abreu says:
> 
>     MMC interrupts were being enabled, which is not what we want because it
>     will lead to a storm of interrupts that are not handled at all. Fix it
>     by disabling all MMC interrupts for XGMAC.

I would add this information the commit message.

> 
>>>
>>> Fixes: aeb18dd07692 ("net: stmmac: xgmac: Disable MMC interrupts by default")
>>> Signed-off-by: Furong Xu <0x1207@xxxxxxxxx>
>>> ---
>>>  drivers/net/ethernet/stmicro/stmmac/mmc_core.c | 4 ++++
>>>  1 file changed, 4 insertions(+)
>>>
>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/mmc_core.c b/drivers/net/ethernet/stmicro/stmmac/mmc_core.c
>>> index ea4910ae0921..cdd7fbde2bfa 100644
>>> --- a/drivers/net/ethernet/stmicro/stmmac/mmc_core.c
>>> +++ b/drivers/net/ethernet/stmicro/stmmac/mmc_core.c
>>> @@ -177,8 +177,10 @@
>>>  #define MMC_XGMAC_RX_DISCARD_OCT_GB	0x1b4
>>>  #define MMC_XGMAC_RX_ALIGN_ERR_PKT	0x1bc
>>>  
>>> +#define MMC_XGMAC_FPE_TX_INTR_MASK	0x204
>>>  #define MMC_XGMAC_TX_FPE_FRAG		0x208
>>>  #define MMC_XGMAC_TX_HOLD_REQ		0x20c
>>> +#define MMC_XGMAC_FPE_RX_INTR_MASK	0x224
>>>  #define MMC_XGMAC_RX_PKT_ASSEMBLY_ERR	0x228
>>>  #define MMC_XGMAC_RX_PKT_SMD_ERR	0x22c
>>>  #define MMC_XGMAC_RX_PKT_ASSEMBLY_OK	0x230
>>> @@ -352,6 +354,8 @@ static void dwxgmac_mmc_intr_all_mask(void __iomem *mmcaddr)
>>>  {
>>>  	writel(0x0, mmcaddr + MMC_RX_INTR_MASK);
>>>  	writel(0x0, mmcaddr + MMC_TX_INTR_MASK);
>>> +	writel(MMC_DEFAULT_MASK, mmcaddr + MMC_XGMAC_FPE_TX_INTR_MASK);
>>> +	writel(MMC_DEFAULT_MASK, mmcaddr + MMC_XGMAC_FPE_RX_INTR_MASK);
>>>  	writel(MMC_DEFAULT_MASK, mmcaddr + MMC_XGMAC_RX_IPC_INTR_MASK);
>>>  }
>>>    
>