Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [RFC PATCH 0/4] mmc: sdhci: Support maximum DMA latency request via PM QoS | Date | Tue, 24 Mar 2015 21:13:01 +0100 |
| |
On Tuesday, March 24, 2015 03:40:36 PM Adrian Hunter wrote: > Hi > > Here are some patches to address an issue with SDHCI > in Intel Baytrail. Intel Baytrail has been observed > sometimes to hang if host controllers are using DMA > while deep C-states are used. Workaround that by > specifying a maximum DMA latency that will prevent > deep C-states. > > The first patch adds a new PM QOS function so that > the SDHCI driver can do a "lazy" cancel of the QoS > request from within its "finish" tasklet. > > The second patch adds support to SDHCI for specifying a > maximum DMA latency. > > The third and fourth patches take that facility into > use for Baytrail. > > Ad hoc testing with Lenovo Thinkpad 10 showed a stress > test could run for at least 24 hours with the patches, > compared to less than an hour without. > > These patches are on top of my driver strength patches > which are on top of my re-tuning patches. > > > Adrian Hunter (4): > PM / QoS: Add pm_qos_cancel_request_lazy() that doesn't sleep > mmc: sdhci: Support maximum DMA latency request via PM QOS > mmc: sdhci-acpi: Fix device hang on Intel BayTrail > mmc: sdhci-pci: Fix device hang on Intel BayTrail
I'm a bit concerned about the CPUID-based blacklisting of things and whether or not the SDHCI driver is the right place for doing that.
Maybe we should do it from within the LPSS driver instead?
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
| |