Messages in this thread | | | Date | Tue, 28 Aug 2012 16:01:45 -0700 | From | "Franky Lin" <> | Subject | Re: [PATCH 2/6] brcmfmac: Handling the interrupt in ISR directly for non-OOB |
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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.
Regards, Franky
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