[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20180308145743.GK3529@ulmo>
Date: Thu, 8 Mar 2018 15:57:43 +0100
From: Thierry Reding <thierry.reding@...il.com>
To: Marcel Ziswiler <marcel@...wiler.com>
Cc: linux-tegra@...r.kernel.org, Dmitry Osipenko <digetx@...il.com>,
Marcel Ziswiler <marcel.ziswiler@...adex.com>,
Stephen Boyd <sboyd@...nel.org>, linux-kernel@...r.kernel.org,
Prashant Gaikwad <pgaikwad@...dia.com>,
Peter De Schrijver <pdeschrijver@...dia.com>,
Jonathan Hunter <jonathanh@...dia.com>,
Michael Turquette <mturquette@...libre.com>,
linux-clk@...r.kernel.org
Subject: Re: [PATCH] clk: tegra: fix pllu rate configuration
On Fri, Feb 23, 2018 at 12:04:51AM +0100, Marcel Ziswiler wrote:
> Turns out latest upstream U-Boot does not configure/enable pllu which
> leaves it at some default rate of 500 kHz:
>
> root@...lis-t30:~# cat /sys/kernel/debug/clk/clk_summary | grep pll_u
> pll_u 3 3 0 500000 0
>
> Of course this won't quite work leading to the following messages:
>
> [ 6.559593] usb 2-1: new full-speed USB device number 2 using tegra-
> ehci
> [ 11.759173] usb 2-1: device descriptor read/64, error -110
> [ 27.119453] usb 2-1: device descriptor read/64, error -110
> [ 27.389217] usb 2-1: new full-speed USB device number 3 using tegra-
> ehci
> [ 32.559454] usb 2-1: device descriptor read/64, error -110
> [ 47.929777] usb 2-1: device descriptor read/64, error -110
> [ 48.049658] usb usb2-port1: attempt power cycle
> [ 48.759475] usb 2-1: new full-speed USB device number 4 using tegra-
> ehci
> [ 59.349457] usb 2-1: device not accepting address 4, error -110
> [ 59.509449] usb 2-1: new full-speed USB device number 5 using tegra-
> ehci
> [ 70.069457] usb 2-1: device not accepting address 5, error -110
> [ 70.079721] usb usb2-port1: unable to enumerate USB device
>
> Fix this by actually allowing the rate also being set from within
> the Linux kernel.
>
> Signed-off-by: Marcel Ziswiler <marcel.ziswiler@...adex.com>
>
> ---
>
> drivers/clk/tegra/clk-pll.c | 2 ++
> 1 file changed, 2 insertions(+)
I'm aware of the discussion about how best to implement this, but this
seems like a reasonable fix until we have something better.
Peter, Jon: if you want to fix this more properly, please take point on
this.
Applied this to for-4.17/clk, thanks.
Thierry
Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)
Powered by blists - more mailing lists