From: Liviu Dudau <liviu@dudau.co.uk>
To: "Bjørn Mork" <bjorn@mork.no>
Cc: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>,
Haijun Liu <haijun.liu@mediatek.com>,
Chiranjeevi Rapolu <chiranjeevi.rapolu@linux.intel.com>,
M Chetan Kumar <m.chetan.kumar@linux.intel.com>,
Ricardo Martinez <ricardo.martinez@linux.intel.com>,
Loic Poulain <loic.poulain@linaro.org>,
Sergey Ryazanov <ryazanov.s.a@gmail.com>,
Johannes Berg <johannes@sipsolutions.net>,
"David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: net: wwan: t7xx: BUG: Unaligned access when loading mtk_t7xx module
Date: Fri, 22 Mar 2024 12:25:19 +0000 [thread overview]
Message-ID: <Zf14r4UPwQss9L4d@bart.dudau.co.uk> (raw)
In-Reply-To: <87il1ezdbd.fsf@miraculix.mork.no>
On Fri, Mar 22, 2024 at 01:00:22PM +0100, Bjørn Mork wrote:
> Liviu Dudau <liviu@dudau.co.uk> writes:
>
> > I had a
> > go at guessing that UL registers are at 0x8 and 0x48 offsets and DL
> > registers are at 0x0478 and 0x04b8, but while that fixes the alignment
> > exception, I now get a "CLDMA{0,1} queue 0 is not empty" message.
>
> I don't think you can assume the register offsets are wrong. It looks
> more like the device doesn't care about alignment.
Sorry, I should clarify: the offsets are wrong when you're trying to do
a 64bit read over PCIe for a MEM64 area. Accessed addresses are expected
to be multiples of 8 bytes. t7xx_cldma_hw_set_start_addr() uses the offset
for the low register for calculating the address for the write, which is
not 64bit aligned for the UL block.
>
> But given that the driver includes <linux/io-64-nonatomic-lo-hi.h>, you
> can probably replace those unaligned 64bit accesses with two nonatomic
> 32bit accesses.
>
I've tried your suggestion and things seem to progress further, thanks for
that! I'm getting some errors on not being able to transition from D3hot
to D0, but I guess it might be something to do with the PCIe-to-M.2 adaptor
that I'm using. Will continue my investigation into the setup and report
back with a patch to replace the register accesses with the lo_hi variants.
Best regards,
Liviu
>
> Bjørn
--
Everyone who uses computers frequently has had, from time to time,
a mad desire to attack the precocious abacus with an axe.
-- John D. Clark, Ignition!
prev parent reply other threads:[~2024-03-22 12:25 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-21 16:51 net: wwan: t7xx: BUG: Unaligned access when loading mtk_t7xx module Liviu Dudau
2024-03-22 12:00 ` Bjørn Mork
2024-03-22 12:25 ` Liviu Dudau [this message]
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