I can't reduce the size of my patch for the e1000e realtime driver existed
in Xenomai, because the non-realtime driver evolutions a lot. So I offered
the diff file of three files I changed when porting the driver. On my view,
the hardware oprations shall be unchanged so I focused on the change of
netdev.c. I modfied param.c and e1000.h changed the private data structure
and parameters a little.
For the question you asked:
- the upstream Linux driver I ported over works fine with my hardware, even
when I try to put a strong pressure on it(UDP broadcast storm).
- when I meet the hardware unit hang, the Tx completion interrupt didn't
dissapper but it do reduced a lot.
- I didn't enable CONFIG_IPIPE_DEBUG_CONTEXT, but I do uses lock in several
places.
- then the TX path
- the interrupt registertion code was shown below:
err = rtdm_irq_request(&adapter->irq_handle,
adapter->pdev->irq, e1000_intr_msi, 0,
netdev->name, adapter);
- I write a new index of ring buffer to TDT register to notify the
hardware there is an packet should be sent.
writel(tx_ring->next_to_use, tx_ring->tail);//after writel, the
interrupt routine shall be launched.
- If the 'event flow' means the event during the transmit process, the
event flow is shown below:
e1000e_xmit_frame send an packet atomicly
e1000_tx_map use DMA to map the
packet(maped before,so just get the DMA address)
e1000_tx_queue make sure the tx ring buffer
index right
write the TDT register to tell hardware to send an packet
after the hardware sent an packet, it supposed to trigger an TX completion
interrupt and the driver shall response:
e1000_intr_msi triggered when Tx/Rx
completion
e1000_clean_tx_irq recycle the transmit resource
By the way, I found that every time master station sent an Ready frame
belongs to RTcfg, this Tx hung shows up. And the comunication
before that works fine: the TDMA sync frame send properly and every stage
before the Ready frame goes well.
If I let it stay in the RTCFG_MAIN_CLIENT_2 stage(so far the master and
slave known each other), master and slave could comunicate
properly. So the Ready frame triggers this problem, but why? An frame of
specific format triggers the hardware hung, why it happens?
Jan Kiszka <jan.kis...@siemens.com> 于2018年11月23日周五 下午7:59写道：
> On 21.11.18 02:36, Means Lee via Xenomai wrote:
> > Sure thing. As I ported e1000e-rt driver from mainline kernel e1000e
> > driver, which
> > the commit id is 089d7720383d7bc9ca6b8824a05dfa66f80d1f41, the patch
> file is
> > kind of huge so I attach them here in this mail.
> > diff-with-nrt.diff is the diff file of mainline driver e1000e and my
> ported
> > driver.
> > diff-with-old-rt-e1000e.diff is the diff file of xenomai v3.0.7 driver
> and
> > my ported driver.
> >
>
> Unified diff ("diff -u"), please. I got that offlist, which is more
> readable,
> but it remains huge.
>
> So, let's analyze systematically:
> - the upstream Linux driver you ported over works fine with your
> hardware, correct?
> - hardware unit hand may mean that no TX completion interrupt arrived -
> can you confirm this based on /proc/xenomai/irq?
> - did you enable CONFIG_IPIPE_DEBUG_CONTEXT? It can reveal invalid lock
> usage (common mistake when porting linux drivers over)
> - then look into the TX path
> - is the interrupt registered properly?
> - is packet submission happening?
> - is any interrupt arriving?
> - compare event flow to vanilla Linux driver (add instrumentation to
> both)
>
> Jan
>
> --
> Siemens AG, Corporate Technology, CT RDA IOT SES-DE
> Corporate Competence Center Embedded Linux
>
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