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! -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
