Re: Questions about the Freescale/NXP QuadSPI controller

[Lukasz Majewski <lukma@denx.de>]

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Hi Frieder,

> Hi Lukasz,
> 
> On 19.09.2018 00:42, Lukasz Majewski wrote:
> > Dear All,
> > 
> > Maybe I do jump a bit off topic here, but...
> > 
> > I've read through the following thread:
> > https://patchwork.ozlabs.org/patch/939885/
> > 
> > And it mentions some issues with reading AHB content (buffers) in
> > fsl-quadspi.c driver discovered when new QuadSPI driver was
> > developed.  
> 
> The only setup with two chips that is known to be problematic with
> the new driver, is when both chips are connected to the same bus
> (e.g. QSPIA) using separate chip selects.

I'm using QSPI0 controller, with two memories connected to QSPI0_A and
QSPI0_B lines.

> 
> Does your board use this kind of setup, or are the two chips
> connected two different buses (QSPIA and QSPIB)?
> 
> Have you tested the new driver? It would be great to receive some
> more feedback.

I will check (test) this new driver. No problem.

> 
> > I do have a setup with qspi0 having two SPI memories connected (2x16
> > MiB), and I'm wondering if anybody has some more info regarding:
> > 
> > (What's more is that there is a bug in
> >   * the "IP Command Read" in the Vybrid.) found here:
> > https://elixir.bootlin.com/linux/v4.19-rc4/source/drivers/mtd/spi-nor/fsl-quadspi.c#L671
> > 
> > I've googled for some errata or known issues for vybryd's QSPI IP
> > block (vf610) but without luck so far ...  
> 
> Unfortunately I don't know the background for this comment.

The comment was added by some Freescale employee when the driver was
added to Linux (by Huang - CC'ed).

> Is your 
> board using VF610?

Yes, it uses vf610 (A5 + M4 cores).

> Do you experience problems?

I've already observed following issue:

For the current QSPI ML driver (fsl-quadspi.c - 4.19-rc3) only half
of the AHB buffer is valid. When I do read the whole one - I do see read
data corruption (on UBI or raw memory). 

This was pointed out in the patch:
https://patchwork.ozlabs.org/patch/675401/

Unfortunately, I did not found any info regarding this problem (in
NXP's errata or other doc).

I will check if this issue shows up on new patches.

Thanks in advance for your help.

> 
> Regards,
> Frieder
> 
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/

Best regards,

Lukasz Majewski

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