On 08/28/2012 04:01 PM, Franky Lin wrote: > On 08/28/2012 03:39 PM, Stephen Warren wrote: >> On 08/28/2012 09:45 AM, Franky Lin wrote: >>> On 08/28/2012 04:13 AM, Wei Ni wrote: >>>> On Tue, 2012-08-28 at 04:06 +0800, Stephen Warren wrote: >>>>> On 08/27/2012 09:24 AM, Arend van Spriel wrote: >>>>>> On 08/27/2012 12:25 PM, Wei Ni wrote: >>>>>>> In case of inband interrupts, if we handle the interrupt in dpc >>>>>>> thread, >>>>>>> two level of thread switching takes place to process wifi >>>>>>> interrupts. >>>>>>> One in SDHCI driver and the other in Wifi driver. This may cause the >>>>>>> system >>>>>>> instability. >> ... >>>>>> Not sure if I can follow this explanation. The isr is called with >>>>>> host >>>>>> claimed (by sdio_irq_thread) and all it does is at a linked list >>>>>> member >>>>>> and signal the dpc thread. After doing this the host is released. >>>>> >>>>> Is the issue something like the ISR handler or first level of >>>>> threading >>>>> does: >>>>> >>>>> * Trigger DPC >>>>> * Re-enable interrupt >>>>> >>>>> So that the interrupt then fires again before the triggered DPC can >>>>> run >>>>> to handle/clear it, thus causing an interrupt storm? >>>>> >>>>> Whereas handling the interrupt directly prevents this race condition? >>>> >>>> Above is my understanding. >>> >>> I understand the issue here and totally agree that we should treat >>> in-band and out-band interrupts differently. But my concern is that the >>> behavior of releasing the host before calling brcmf_sdbrcm_isr and grab >>> it after is likely error prone. Also we are restructuring the dpc >>> routine internally and it's almost done. I will find a better solution >>> for in-band interrupt and get it the queue as well. So I suggest >>> dropping this patch. >> >> Franky, do you know which kernel release the DPC restructuring will make >> it into? I ask because I can't apply the rest of the patches in this >> series without first resolving the stability issues with the Broadcom >> WiFi enabled, since that'd de-stabilize the Tegra platform >> significantly, and I'd like to plan when we can apply these patches to >> Tegra. Thanks! >> > > Hi Stephen, > > Since we submit patches through linux-wireless tree, you may only be > able to pick it up at 3.7-rc1. It's quite a big change so I don't think > it will qualify as a bug fix to get into 3.6-rcX. That's as quick as I expected it to show up, so that's great. I don't suppose you could mail Wei and myself once the patch gets into the linux-wireless tree, so we can test it out on Tegra. If the patch could possibly go into a topic branch in the wireless tree so it can be merged into the Tegra tree before this series, that would be awesome. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
