Re: Trouble with DMA on PPC linux question

2016-04-19 Thread Bruce_Leonard
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

Trouble with DMA on PPC linux question

2016-04-18 Thread Bruce_Leonard
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

Re: Question about GPIO Lib

2012-01-31 Thread Bruce_Leonard
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

Re: Question about GPIO Lib

2012-01-30 Thread Bruce_Leonard
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.

Another FSL SPI driver question (warning long post)

2012-01-26 Thread Bruce_Leonard
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

Question about GPIO Lib

2012-01-26 Thread Bruce_Leonard
(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

[no subject]

2012-01-26 Thread Bruce_Leonard
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

Re: FSL SPI driver question

2012-01-26 Thread Bruce_Leonard
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

Re: FSL SPI driver question

2012-01-25 Thread Bruce_Leonard
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

FSL SPI driver question

2012-01-24 Thread Bruce_Leonard
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

Re: MPC8308 bursting question

2011-05-27 Thread Bruce_Leonard
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

MPC8308 bursting question

2011-05-26 Thread Bruce_Leonard
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

Re: Question on supporting multiple HW versions with a single driver (warning: long post)

2011-02-08 Thread Bruce_Leonard
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

Re: Question on supporting multiple HW versions with a single driver (warning: long post)

2011-02-07 Thread Bruce_Leonard
> > 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 __

Question on supporting multiple HW versions with a single driver (warning: long post)

2011-02-02 Thread Bruce_Leonard
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

Re: Question about combining a PCI driver with an OF driver

2011-01-04 Thread Bruce_Leonard
> > > 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

Re: Question about combining a PCI driver with an OF driver

2011-01-04 Thread Bruce_Leonard
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

Question about combining a PCI driver with an OF driver

2011-01-04 Thread Bruce_Leonard
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

Re: Question regarding the DTLB Miss exceptions

2010-04-11 Thread Bruce_Leonard
> > > > 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

Re: Question regarding the DTLB Miss exceptions

2010-04-08 Thread Bruce_Leonard
> > 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

Question regarding the DTLB Miss exceptions

2010-03-29 Thread Bruce_Leonard
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

Need help with using the BDI2K to debug exception handlers

2010-03-10 Thread Bruce_Leonard
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