[PATCH 0/2] spi: imx: don't loop endlessly

[Uwe Kleine-König]

On Wed, Aug 02, 2017 at 09:54:40PM +0200, Sam Ravnborg wrote:
> Hi Uwe.
> 
> On Wed, Aug 02, 2017 at 09:39:05PM +0200, Uwe Kleine-König wrote:
> > Hello,
> > 
> > during bringup of an i.MX7 board I am faced with cspi_2_3_xchg_single not
> > returning. I don't know yet why this happens, but with this patch set it at least
> > doesn't block barebox.
> 
> Your description reminded me of a similar issue we hit with SPI transfer.
> Back then Sascha fixed it but with some open question marks.
> 
> See 9da7e18573c725eaa6123c401df57d6a4f6a0ea2
> ("spi: i.MX: reset controller on init")
> 
> But as this is the latest patch to the imx_spi.c file you likely
> have already looked at it.

I havn't looked at it, but it is included in my barebox as I'm using
2017.08.0 + some patches.

Reading through the patch description, it doesn't match my situation.
I'm doing USB-Booting because when I made eMMC work all my available
remote hands already called it a day. So unless the boot ROM does
something strange (impossible!) barebox is the first spi user.

What seems to be similar is that TESTREG.TXCNT is != 0. For me this
smells clk-related. On i.MX6 I recently identified a problem (but didn't
come around yet to mainline a fix) that might match at least your
problem.

Can you still reproduce? How does your clk-tree look like (clk_dump)?

Thanks for your attention
Uwe

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Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |