Messages in this thread | | | Date | Mon, 12 Mar 2012 12:09:43 -0600 | From | Stephen Warren <> | Subject | Re: [PATCH v2 2/2] arm/tegra: add timeout to PCIe PLL lock detection loop |
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On 03/09/2012 03:09 AM, Dmitry Artamonow wrote: > Tegra PCIe driver waits for PLL to lock using busy loop. > If PLL fails to lock for some reason, this leads to silent lockup > while booting (PCIe code is not modular). > > Fix by adding timeout, so if PLL doesn't lock in a couple > of seconds, just PCIe driver fails and machine continues to boot. > > Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru>
> diff --git a/arch/arm/mach-tegra/pcie.c b/arch/arm/mach-tegra/pcie.c
> /* Wait for the PLL to lock */ > + timeout = 2000; > do { > val = pads_readl(PADS_PLL_CTL); > + usleep_range(1000, 1000); > + if (--timeout == 0) { > + pr_err("Tegra PCIe error: timeout waiting for PLL\n"); > + return -EBUSY; > + } > } while (!(val & PADS_PLL_CTL_LOCKDET));
Thierry pointed out that one of NVIDIA's downstream kernels uses a timeout of 300 here, rather than 2000 above. Do you see a specific need for this timeout for be 2000 rather than 300? It might be nice to be consistent.
Olof, I notice you've already applied V1 of this, which has the return statement issue. Can you replace it with this, or should Dmitry send an incremental patch?
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