Re: [PATCH 1/2] hw/net/net_tx_pkt: add function to check pkt->max_raw_frags

[Jason Wang <jasowang@redhat.com>]

On 2020/7/31 上午1:05, Mauro Matteo Cascella wrote:
> On Thu, Jul 30, 2020 at 7:28 AM Jason Wang<jasowang@redhat.com>  wrote:
>> On 2020/7/29 上午12:26, Mauro Matteo Cascella wrote:
>>> On Tue, Jul 28, 2020 at 6:06 AM Jason Wang<jasowang@redhat.com>  wrote:
>>>> On 2020/7/28 上午1:08, Mauro Matteo Cascella wrote:
>>>>> This patch introduces a new function in hw/net/net_tx_pkt.{c,h} to check the
>>>>> current data fragment against the maximum number of data fragments.
>>>> I wonder whether it's better to do the check in
>>>> net_tx_pkt_add_raw_fragment() and fail there.
>>> Given the assertion, I assumed the caller is responsible for the
>>> check, but moving the check in net_tx_pkt_add_raw_fragment() totally
>>> makes sense to me.
>> Want to send a new version for this?
> Sure, I'll send a new version. Thank you.
>
>>>> Btw, I find net_tx_pkt_add_raw_fragment() does not unmap dma when
>>>> returning to true, is this a bug?
>>> Isn't it unmapped in net_tx_pkt_reset()?
>> Probably but see how it was used in e1000e, the net_tx_pkt_reset() is
>> only called when eop is set. Is this a bug?
> Yeah it all depends on E1000_TXD_CMD_EOP. Besides, if not set,
> e1000e_tx_pkt_send() would never be called. Honestly, I don't know if
> this is a reasonable scenario or not.


It's probably fine since anyway e1000e_core_reset() will call 
net_tx_pkt_reset().

Thanks


>
>> Thanks
>>