Ben,
Benjamin Herrenschmidt wrote on 04/19/2016 01:45:40 AM:
> From: Benjamin Herrenschmidt
> To: bruce_leon...@selinc.com, linuxppc-dev@lists.ozlabs.org
> Date: 04/19/2016 01:46 AM
> Subject: Re: Trouble with DMA on PPC linux question
>
> On Mon, 2016-04-18 at 14:54 -0700, bruce_leon...@selin
Good afternoon everyone,
We're trying to get some performance gains in an older embedded design by
adding DMA to our NAND driver. The HW is an MPC8349 talking across a PCI
bus to a NAND controller and we have 512Mb of RAM. We're using the 3.18
kernel and the Freescale "fsl,mpc8349-dma" driver
Bill,
Bill Gatliff wrote on 01/31/2012 08:39:05 AM:
>
> I misunderstood your message, then. I was thinking that you were
>
No worries, I frequently misunderstand myself :) Thanks for taking the
time to respond, I appreciate it.
> I'm DEFINITELY not saying that gpiolib is generally a waste
Bill,
Bill Gatliff wrote on 01/27/2012 10:42:57 AM:
>
> On Fri, Jan 27, 2012 at 5:31 AM, wrote:
> >
> > The problem is we've got a number of other things hooked up to the
GPIO
> > pins that it would be very bad if someone from user space played with
> > them, like our FPGA configuration pin.
Hi Kumar,
I'm using the 3.0.3 kernel on an MPC8308 and utilizing the spi_fsl_spi
driver to talk with an Cypress NvRAM device. I've gotten that working
now, but I've come across something I don't understand in the driver and
I'm not sure if it's just me or if there's a bug. My issue relates to
(This time with a subject line, sorry)
Hi,
I'm using the 3.0.3 kernel on an MPC8308 and have turned on GPIO support
(CONFIG_GPIOLIB = Y) because the SPI sub-system needed to use it for the
GPIO pin I'm using as a CS to a NvRAM part. I also have some jumpers on
the processor GPIO pins and I th
Hi,
I'm using the 3.0.3 kernel on an MPC8308 and have turned on GPIO support
(CONFIG_GPIOLIB = Y) because the SPI sub-system needed to use it for the
GPIO pin I'm using as a CS to a NvRAM part. I also have some jumpers on
the processor GPIO pins and I thought it would be really slick to use th
Norbert,
>
> ok, then I don't know.
>
> I doubt this is a spidev or FSP SPI driver problem though.
>
> Questions like:
>
> Could it be a HW problem ?
> Is the correct SPI mode used ?
> Does it work in u-boot ?
>
> Come to mind in a situation like this.
>
Thanks for the suggestions. I final
Hi Norbert,
> >
> > So the question is, how do I use spidev (or any other means) to get
the
> > 8308 SPI controller to keep SPICLK active so that the output data from
the
> > NvRAM gets clocked out to the 8308?
> >
>
> Did you see Documentation/spi/spidev_fdx.c:do_msg ?
> it perform a full-dupl
Good afternoon,
I'm using the 3.0.3 kernel running on an MPC8308 and am trying to
interface to a Cypress CY14B256Q2A non-volatile RAM via SPI. I've got the
SPI infrastructure, the Freescale SPI driver (drivers/spi/spi_fsl_spi.c),
and spidev built into the kernel and everything on the user spac
Hi David,
>
> Read my MPC8349EA UPM setup notes and see if you have used
> similar settings (I assume the local bus UPMs are similar):
>
I found you paper interesting. I didn't have a problem with my UPM
settings, single beat reads and writes worked just fine, however it did
tickle my memory
All,
This isn't really a Linux PPC question, but this is the smartest mailing
list I know for asking PPC hardware questions, so here goes.
We're using an MPC8308 and want to use the DMA engine to move data in and
out of an FPGA hanging on the local bus. Our bandwidth/local bus burden
calculat
Ah, okay. Taking a look at that it makes sense now. Thanks to both of
you for the help.
Bruce
From:
Bill Gatliff
To:
bruce_leon...@selinc.com
Cc:
David Gibson , linuxppc-dev@lists.ozlabs.org
Date:
02/07/2011 09:13 PM
Subject:
Re: Question on supporting multiple HW versions with a single dri
>
> There are a number of drivers which already have this sort of dual bus
> binding.
>
Thanks for the feedback David, I appreciate it. Could you point me to one
of those drivers that has "this sort of dual bus binding" so can see an
example of what I'm trying to do?
Bruce
__
So this is sort of a follow on question to one I posted a month ago about
trying to get a PCI driver to work with OF (which I think I more or less
understood the answer to). I'm encountering a different sort of problem
that I'd like to solve with OF but I'm not sure I can. Let me lay out a
li
>
> > Okay, I get that and it makes sense with what I know so far about how
the
> > kernel device model works (which I'm still learning). So how would I
> > manually add a device? Say I create the PCI wrapper driver that
claims
> > the clone-TSEC, is there a "register device" type call simi
Scott,
Thanks for the feedback.
>
> Making a faithful clone of any reasonably complex device strikes me as
> more work than writing a new ethernet driver.
>
> The last thing you want to end up doing is...
>
> > And for speed sake it would go on the PCI bus.
> > (So much for letting HW make d
Hi all,
I'm working on a project with an MPC8347 and three ethernet ports. Because
of end of life issues we've had to replace the part we're using for the
third ethernet port and we decided rather than rely on a vendor who would
pull a part out from under us every two to three years we would do
> >
> > It's checking to see if the following bits of DSISR are set:
> > 0 - set by DTLB miss if no hash table entry group is found
>
> No. 0 means we hit a direct store segment. This is a historical feature
> of the architecture which we don't use, so should not happen.
>
Sorry, would have hel
> > When a DTLB Miss exception can't find a PTE for the virtual address
being
> > written/read, it dummies up the SPRs for a DSI exception and then
calls
> > directly into the DSI exception code. Just before the DTLB miss code
> > stores a value into DSISR it sets bit 2, which for a DSI excep
I'm tracking a problem that's leading me through DSI and DTLB miss
exceptions on an MPC8347 (e300c1 core), and I've come across an oddity
that I'm hoping someone can explain.
When a DTLB Miss exception can't find a PTE for the virtual address being
written/read, it dummies up the SPRs for a DSI
Hi all,
Okay, I'm putting on my asbestos underwear and hoping I don't sound too
stupid. Here's my sitch: we're seeing an illegal instruction exception,
but the tracks our diagnostic code we put into the kernel
program_check_exception() function claims the instruction is perfectly
good. So I
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