Re: [PATCH 3/3] gianfar: fix endianness for hardware timestamp

[YOSHIFUJI Hideaki]

Hi,

Yangbo Lu wrote:
>> -Original Message-
>> From: Richard Cochran [mailto:richardcoch...@gmail.com]
>> Sent: Monday, February 22, 2016 4:48 PM
>> To: Yangbo Lu
>> Cc: netdev@vger.kernel.org; Claudiu Manoil
>> Subject: Re: [PATCH 3/3] gianfar: fix endianness for hardware timestamp
>>
>> On Mon, Feb 22, 2016 at 02:49:33PM +0800, Yangbo Lu wrote:
>>> @@ -2708,6 +2708,7 @@ static void gfar_clean_tx_ring(struct
>> gfar_priv_tx_q *tx_queue)
>>> struct skb_shared_hwtstamps shhwtstamps;
>>> u64 *ns = (u64 *)(((uintptr_t)skb->data + 0x10) &
>>>   ~0x7UL);
>>> +   *ns = be64_to_cpu(*ns);
>>>
>>> memset(, 0, sizeof(shhwtstamps));
>>> shhwtstamps.hwtstamp = ns_to_ktime(*ns);
>>
>> There is no point in modifying the buffer data in place.
>>
>> Instead, do this:
>>
>>  memset(, 0, sizeof(shhwtstamps));
>>  shhwtstamps.hwtstamp = ns_to_ktime(be64_to_cpu(*ns));
>>
>> or this:
>>
>>  u64 ns, *ptr = (u64 *)(((uintptr_t)skb->data + 0x10) &
>> ~0x7UL);
>>  ns = be64_to_cpu(*ptr);
>>
>>  memset(, 0, sizeof(shhwtstamps));
>>  shhwtstamps.hwtstamp = ns_to_ktime(ns);
>>
> 
> [Lu Yangbo-B47093] I will modify codes according your suggestion.
> Thank you so much!

You may want to use PTR_ALIGN() and be64_to_cpup() here.

--yoshfuji

>  
>>> @@ -3037,6 +3038,7 @@ static void gfar_process_frame(struct net_device
>> *ndev, struct sk_buff *skb)
>>> if (priv->hwts_rx_en) {
>>> struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
>>> u64 *ns = (u64 *) skb->data;
>>> +   *ns = be64_to_cpu(*ns);
>>>
>>> memset(shhwtstamps, 0, sizeof(*shhwtstamps));
>>> shhwtstamps->hwtstamp = ns_to_ktime(*ns);
>>
>> Same here.
>>
>> Thanks,
>> Richard

-- 
Hideaki Yoshifuji <hideaki.yoshif...@miraclelinux.com>
Technical Division, MIRACLE LINUX CORPORATION

RE: [PATCH 3/3] gianfar: fix endianness for hardware timestamp

[Yangbo Lu]

> -Original Message-
> From: Richard Cochran [mailto:richardcoch...@gmail.com]
> Sent: Monday, February 22, 2016 4:48 PM
> To: Yangbo Lu
> Cc: netdev@vger.kernel.org; Claudiu Manoil
> Subject: Re: [PATCH 3/3] gianfar: fix endianness for hardware timestamp
> 
> On Mon, Feb 22, 2016 at 02:49:33PM +0800, Yangbo Lu wrote:
> > @@ -2708,6 +2708,7 @@ static void gfar_clean_tx_ring(struct
> gfar_priv_tx_q *tx_queue)
> > struct skb_shared_hwtstamps shhwtstamps;
> > u64 *ns = (u64 *)(((uintptr_t)skb->data + 0x10) &
> >   ~0x7UL);
> > +   *ns = be64_to_cpu(*ns);
> >
> > memset(, 0, sizeof(shhwtstamps));
> > shhwtstamps.hwtstamp = ns_to_ktime(*ns);
> 
> There is no point in modifying the buffer data in place.
> 
> Instead, do this:
> 
>   memset(, 0, sizeof(shhwtstamps));
>   shhwtstamps.hwtstamp = ns_to_ktime(be64_to_cpu(*ns));
> 
> or this:
> 
>   u64 ns, *ptr = (u64 *)(((uintptr_t)skb->data + 0x10) &
>  ~0x7UL);
>   ns = be64_to_cpu(*ptr);
> 
>   memset(, 0, sizeof(shhwtstamps));
>   shhwtstamps.hwtstamp = ns_to_ktime(ns);
> 

[Lu Yangbo-B47093] I will modify codes according your suggestion.
Thank you so much!
 
> > @@ -3037,6 +3038,7 @@ static void gfar_process_frame(struct net_device
> *ndev, struct sk_buff *skb)
> > if (priv->hwts_rx_en) {
> > struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
> > u64 *ns = (u64 *) skb->data;
> > +   *ns = be64_to_cpu(*ns);
> >
> > memset(shhwtstamps, 0, sizeof(*shhwtstamps));
> > shhwtstamps->hwtstamp = ns_to_ktime(*ns);
> 
> Same here.
> 
> Thanks,
> Richard

Re: [PATCH 3/3] gianfar: fix endianness for hardware timestamp

[Richard Cochran]

On Mon, Feb 22, 2016 at 02:49:33PM +0800, Yangbo Lu wrote:
> Signed-off-by: Yangbo Lu 

Commit message is missing.

Thanks,
Richard

Re: [PATCH 3/3] gianfar: fix endianness for hardware timestamp

[Richard Cochran]

On Mon, Feb 22, 2016 at 02:49:33PM +0800, Yangbo Lu wrote:
> @@ -2708,6 +2708,7 @@ static void gfar_clean_tx_ring(struct gfar_priv_tx_q 
> *tx_queue)
>   struct skb_shared_hwtstamps shhwtstamps;
>   u64 *ns = (u64 *)(((uintptr_t)skb->data + 0x10) &
> ~0x7UL);
> + *ns = be64_to_cpu(*ns);
>  
>   memset(, 0, sizeof(shhwtstamps));
>   shhwtstamps.hwtstamp = ns_to_ktime(*ns);

There is no point in modifying the buffer data in place.

Instead, do this:

memset(, 0, sizeof(shhwtstamps));
shhwtstamps.hwtstamp = ns_to_ktime(be64_to_cpu(*ns));

or this:

u64 ns, *ptr = (u64 *)(((uintptr_t)skb->data + 0x10) &
   ~0x7UL);
ns = be64_to_cpu(*ptr);

memset(, 0, sizeof(shhwtstamps));
shhwtstamps.hwtstamp = ns_to_ktime(ns);

> @@ -3037,6 +3038,7 @@ static void gfar_process_frame(struct net_device *ndev, 
> struct sk_buff *skb)
>   if (priv->hwts_rx_en) {
>   struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
>   u64 *ns = (u64 *) skb->data;
> + *ns = be64_to_cpu(*ns);
>  
>   memset(shhwtstamps, 0, sizeof(*shhwtstamps));
>   shhwtstamps->hwtstamp = ns_to_ktime(*ns);

Same here.

Thanks,
Richard