On Thu, Mar 26, 2020 at 3:18 AM Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote: > > > Hi Saravana, > > On 25/03/2020 23:56, Saravana Kannan wrote: > > On Wed, Mar 25, 2020 at 2:47 PM Thomas Gleixner > > <tglx@xxxxxxxxxxxxx> wrote: > >> > >> Saravana Kannan <saravanak@xxxxxxxxxx> writes: > >>> On Tue, Mar 24, 2020 at 11:34 AM Saravana Kannan > >>> <saravanak@xxxxxxxxxx> wrote: I took a closer look. So two > >>> different drivers [1] [2] are saying they know how to handle > >>> "arm,vexpress-sysreg" and are expecting to run at the same > >>> time. That seems a bit unusual to me. I wonder if this is a > >>> violation of the device-driver model because this expectation > >>> would never be allowed if these device drivers were actual > >>> drivers registered with driver-core. But that's a discussion > >>> for another time. > >>> > >>> To fix this issue you are facing, this patch should work: > >>> https://lore.kernel.org/lkml/20200324195302.203115-1-saravanak@xxxxxxxxxx/T/#u > >> > >> > >>> > >>> > >>> > > Sorry, that's not a fix. That's a crude hack. > > > > If device nodes are being handled by drivers without binding a > > driver to struct devices, then not setting OF_POPULATED is wrong. > > So the original patch sets it. There are also very valid reasons > > for allowing OF_POPULATED to be cleared by a driver as discussed > > here [1]. > > > > The approach of the original patch (setting the flag and letting > > the driver sometimes clear it) is also followed by many other > > frameworks like irq, clk, i2c, etc. Even ingenic-timer.c already > > does it for the exact same reason. > > > > So, why is the vexpress fix a crude hack? > > > >> As this is also causing trouble on tegra30-cardhu-a04 the only > >> sane solution is to revert it and start over with a proper > >> solution for the vexpress problem and a root cause analysis for > >> the tegra. > > > > If someone can tell me which of the timer drivers are relevant for > > tegra30-cardhu-a04, I can help fix it. If you want to revert the > > original patch first before waiting for a tegra fix, that's okay by > > me. > > > It seems the OF_POPULATED flag change spotted something wrong in > different drivers and that is a good thing. Thanks for your patch for > that. > > Without putting in question your analysis, we need to stabilize the > release, can you send a revert of your patch? > > Let's try to figure out what is happening and fix the issues in the > other drivers for the next cycle. Make sense. Will do soon. -Saravana > > Thanks > > -- Daniel > > > > -- > <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs > > Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | > <http://twitter.com/#!/linaroorg> Twitter | > <http://www.linaro.org/linaro-blog/> Blog
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