On 2/2/2016 11:07 AM, Zhang, Helin wrote: > >> -----Original Message----- >> From: Qiu, Michael >> Sent: Tuesday, February 2, 2016 10:57 AM >> To: Zhang, Helin <helin.zhang at intel.com>; Lu, Wenzhuo >> <wenzhuo.lu at intel.com>; dev at dpdk.org >> Cc: Zhou, Danny <danny.zhou at intel.com>; Liu, Yong <yong.liu at intel.com>; >> Liang, Cunming <cunming.liang at intel.com> >> Subject: Re: [PATCH v2] ixgbe: Fix disable interrupt twice >> >> On 2/2/2016 10:14 AM, Zhang, Helin wrote: >>>> -----Original Message----- >>>> From: Qiu, Michael >>>> Sent: Tuesday, February 2, 2016 10:07 AM >>>> To: Lu, Wenzhuo; dev at dpdk.org >>>> Cc: Zhou, Danny; Liu, Yong; Liang, Cunming; Zhang, Helin >>>> Subject: Re: [PATCH v2] ixgbe: Fix disable interrupt twice >>>> >>>> [+cc helin] >>>> >>>> On 2/2/2016 9:03 AM, Lu, Wenzhuo wrote: >>>>> Hi Michael, >>>>> >>>>>> -----Original Message----- >>>>>> From: Qiu, Michael >>>>>> Sent: Monday, February 1, 2016 4:05 PM >>>>>> To: Lu, Wenzhuo; dev at dpdk.org >>>>>> Cc: Zhou, Danny; Liu, Yong; Liang, Cunming >>>>>> Subject: Re: [PATCH v2] ixgbe: Fix disable interrupt twice >>>>>> >>>>>> On 1/29/2016 4:07 PM, Lu, Wenzhuo wrote: >>>>>>> Hi Michael, >>>>>>> >>>>>>>> -----Original Message----- >>>>>>>> From: Qiu, Michael >>>>>>>> Sent: Friday, January 29, 2016 1:58 PM >>>>>>>> To: dev at dpdk.org >>>>>>>> Cc: Zhou, Danny; Liu, Yong; Liang, Cunming; Lu, Wenzhuo; Qiu, >>>>>>>> Michael >>>>>>>> Subject: [PATCH v2] ixgbe: Fix disable interrupt twice >>>>>>>> >>>>>>>> Currently, ixgbe vf and pf will disable interrupt twice in stop >>>>>>>> stage and uninit stage. It will cause an error: >>>>>>>> >>>>>>>> testpmd> quit >>>>>>>> >>>>>>>> Shutting down port 0... >>>>>>>> Stopping ports... >>>>>>>> Done >>>>>>>> Closing ports... >>>>>>>> EAL: Error disabling MSI-X interrupts for fd 26 >>>>>>>> Done >>>>>>>> >>>>>>>> Becasue the interrupt already been disabled in stop stage. >>>>>>>> Since it is enabled in init stage, better remove from stop stage. >>>>>>> I'm afraid it?s not a good idea to just remove the intr_disable >>>>>>> from >>>> dev_stop. >>>>>>> I think dev_stop have the chance to be used independently with >>>>>>> dev_unint. In >>>>>> this scenario, we still need intr_disable, right? >>>>>>> Maybe what we need is some check before we disable the intr:) >>>>>> Yes, indeed we need some check in disable intr, but it need >>>>>> additional fields in "struct rte_intr_handle", and it's much saft >>>>>> to do so, but as I check i40e/fm10k code, only ixgbe disable it in >> dev_stop(). >>>>> I found fm10k doesn?t enable intr in dev_start. So, I think it's OK. >>>>> But i40e >>>> enables intr in dev_start. >>>>> To my opinion, it's more like i40e misses the intr_disable in dev_stop. >>>> I don't think i40e miss it, because it not the right please to disable >>>> interrupt. >>>> because all interrupts are enabled in init stage. >>>> >>>> Actually, ixgbe enable the interrupt in init stage, but in dev_start, >>>> it disable it first and re-enable, so it just the same with doing nothing >>>> about >> interrupt. >>>> Just think below: >>>> >>>> 1. start the port.(interrupt already enabled in init stage, disable >>>> --> >>>> re-enable) >>>> 2. stop the port.(disable interrupt) >>>> 3. start port again(Try to disable, but failed, already disabled) >>>> >>>> Would you think the code has issue? >>> [Zhang, Helin] in ixgbe PMD, it can be seen that uninit() calls >>> dev_close(), which calls dev_stop(). So I think the disabling can be done >>> only in >> dev_stop(). >>> All others can make use of dev_stop to disable the interrupt. >> As I said, if it is in dev_stop, it will has issue when dev_start --> >> dev_stop --> >> dev_start, this also could applied in i40e and fm10k. If you want to put it >> in >> dev_stop, better to remove enable interrupts in init stage, and only put it >> in >> dev_start. > Oh, yes, you are talking about the refactoring. That's good, and reasonable. > Please do more validation with LSC, mailbox, rx interrupts, to make sure there > is no issue introduced.
I have no plan to do code refactor, it includes lots of validation, and will influence many components, time is limited for 2.3. I would like keep it in uninit and remove it from stop, this only affect ixgbe, and I have done validation for it. Thanks, Michael > Thanks, > Helin > >> Thanks, >> Michael >>> Regards, >>> Helin >>> >>>> Thanks, >>>> Michael >>>> >>>>> Maybe we can follow fm10k's style. >>>>> >>>>>> On other hand, if we remove it in dev_stop, any side effect? In >>>>>> ixgbe start, it will always disable it first and then re-enable it, so >>>>>> it's safe. >>>>> I think you mean we can disable intr anyway even if it has been disabled. >>>> Actually, we couldn't, DPDK call VFIO ioctl to kernel to disable >>>> interrupts, and if we try disable twice, it will return and error. >>>> That's why I mean we need a flag to show the interrupts stats. If it >>>> already disabled, we do not need call in to kernel. just return and >>>> give a warning message. >>>> >>>> Thanks, >>>> Michael >>>> >>>>> Sounds more like why we don't >>>>> need this patch :) >>>>> >>>>>> Thanks, >>>>>> Michael >
