Boot time regression on Xilinx Zynq7000

[Rajan Vaja]

Hi Michal

> -----Original Message-----
> From: Michal Simek <michal.simek at xilinx.com>
> Sent: 08 July 2020 11:32 AM
> To: Daniel Mack <daniel at zonque.org>; linux-arm-kernel at lists.infradead.org
> Cc: Rajan Vaja <RAJANV at xilinx.com>; Michal Simek <michals at xilinx.com>; Daniel
> Lezcano <daniel.lezcano at linaro.org>
> Subject: Re: Boot time regression on Xilinx Zynq7000
> 
> 
> 
> On 26. 06. 20 8:51, Daniel Mack wrote:
> > Hi,
> >
> > I'm seeing a regression on a Zynq7000 board between 5.5 and 5.6 and
> > bisected it down to f5ac896b6a23eb ("clocksource/drivers/cadence-ttc:
> > Use ttc driver as platform driver"). With the patch in place, I see a 5
> > second delay in the kernel boot:
> >
> > [    1.540000] random: fast init done
> > [    1.690000] random: crng init done
> > [    2.720000] libphy: mdio: probed
> >
> > -- boot freezes for about 5 seconds --
> >
> > [    7.780000] i2c /dev entries driver
> > [    7.800000] cdns-i2c e0004000.i2c: 100 kHz mmio e0004000 irq 21
> > [    7.800000] cdns-i2c e0005000.i2c: 100 kHz mmio e0005000 irq 22
> > [    7.810000] EDAC MC: ECC not enabled
> > [    7.820000] Xilinx Zynq CpuIdle Driver started
> > [    7.820000] sdhci: Secure Digital Host Controller Interface driver
> > [    7.830000] sdhci: Copyright(c) Pierre Ossman
> > [    7.830000] sdhci-pltfm: SDHCI platform and OF driver helper
> > [    7.870000] mmc0: SDHCI controller on e0100000.mmc [e0100000.mmc]
> > using ADMA
> > [    7.870000] ledtrig-cpu: registered to indicate activity on CPUs
> > [    7.880000] clocksource: ttc_clocksource: mask: 0xffff max_cycles:
> > 0xffff, max_idle_ns: 537538477 ns
> > [    7.890000] clocksource: Switched to clocksource ttc_clocksource
> >
> >
> > Reverting the patch on top of 5.6 solves this issue. I haven't dug any
> > further yet. Any idea?
> 
> Rajan: Can you please take a look at it?
[Rajan] Sure. I will look into this.

Thanks,
Rajan
> 
> Thanks,
> Michal