Hi Han,
On 12.09.2018 19:04, Han Xu wrote:
-----Original Message-----
From: Frieder Schrempf [mailto:frieder.schrempf@xxxxxxxxx]
Sent: Monday, September 3, 2018 4:02 AM
To: Han Xu <han.xu@xxxxxxx>
Cc: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>; David Wolfe
<david.wolfe@xxxxxxx>; Fabio Estevam <fabio.estevam@xxxxxxx>;
Prabhakar Kushwaha <prabhakar.kushwaha@xxxxxxx>; Yogesh Narayan
Gaur <yogeshnarayan.gaur@xxxxxxx>; shawnguo@xxxxxxxxxx; linux-
mtd@xxxxxxxxxxxxxxxxxxx; linux-spi@xxxxxxxxxxxxxxx; dwmw2@xxxxxxxxxxxxx;
computersforpeace@xxxxxxxxx; marek.vasut@xxxxxxxxx; richard@xxxxxx;
miquel.raynal@xxxxxxxxxxx; broonie@xxxxxxxxxx
Subject: Re: Questions about the Freescale/NXP QuadSPI controller
Hi Han,
On 04.08.2018 15:37, Boris Brezillon wrote:
Hi Han,
On Thu, 2 Aug 2018 21:58:48 +0000
Han Xu <han.xu@xxxxxxx> wrote:
-----Original Message-----
From: Frieder Schrempf [mailto:frieder.schrempf@xxxxxxxxx]
Sent: Thursday, August 2, 2018 8:09 AM
To: David Wolfe <david.wolfe@xxxxxxx>; Fabio Estevam
<fabio.estevam@xxxxxxx>; Prabhakar Kushwaha
<prabhakar.kushwaha@xxxxxxx>; Yogesh Narayan Gaur
<yogeshnarayan.gaur@xxxxxxx>; Han Xu <han.xu@xxxxxxx>;
shawnguo@xxxxxxxxxx
Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx; boris.brezillon@xxxxxxxxxxx;
linux- spi@xxxxxxxxxxxxxxx; dwmw2@xxxxxxxxxxxxx;
computersforpeace@xxxxxxxxx; marek.vasut@xxxxxxxxx;
richard@xxxxxx;
miquel.raynal@xxxxxxxxxxx; broonie@xxxxxxxxxx
Subject: Re: Questions about the Freescale/NXP QuadSPI controller
Ping.
I'm not sure if my message below went out to you at all. At least I
can't find it in the ML archive.
I still hope someone can help with the questions below.
Meanwhile for the second point I did some tests myself with one chip
on each of the two buses and it worked fine with my latest v2 patches.
So I'm not sure at all why Yogesh has problems with his setup (two
chips on the first bus).
Tried to test the v2 patch set on i.MX6SX SDB board but get the memory
map failure.
[ 1.298633] fsl-quadspi 21e4000.qspi: ioremap failed for resource [mem
0x70000000-0x7fffffff]
[ 1.307330] fsl-quadspi 21e4000.qspi: Freescale QuadSPI probe failed
[ 1.313922] fsl-quadspi: probe of 21e4000.qspi failed with error -12
This is the reason why dynamic ioremap added in previous driver, please
refer to
https://smex12-5-en-ctp.trendmicro.com:443/wis/clicktime/v1/query?url=https%3a%2f%2femea01.safelinks.protection.outlook.com%2f%3furl%3dhttps%253A%252F%252Fpa&umid=d6cc1014-1848-42fb-92fd-9626d45c8050&auth=541e45255b6517100d80c2b1b80b6933b203c492-5aa8e1977a9db94300a9f61f5446e7a21b175f56
tchwork.ozlabs.org%2Fpatch%2F503655%2F&data=02%7C01%7Chan.xu
%40nx
p.com%7C9f45a8b666d3478f065408d6117bf524%7C686ea1d3bc2b4c6fa92cd9
9c5c
301635%7C0%7C0%7C636715621426190473&sdata=XWPfWe%2Fu2ePW
mNPe179D0
vjTp6eLp0%2FJRF2vRayDwug%3D&reserved=0
We can reduce the size of the iomap to 2k * 4, since this is all we
use currently. Can you try to change the size of the ioremap call to
16k and tell us if it works.
Were you able to test with the reduced iomap size?
It would be great to know if it works on your board.
Thanks,
Frieder
Test the code on i.MX6SX sabreauto board with two micron n25q256a chips on two CS.
First issue found is __div0 kernel dump with these code
/* Max 64 dummy clock cycles supported */
if (op->dummy.nbytes * 8 / op->dummy.buswidth > 64)
dummy.buswidth was not set during read id.
First, thank you for coming back to this and doing the test.
I'm currently not sure about the reason for this, but I guess Boris will
figure it out easily ;)
Second issue is the second part failed to be probed, tried both buswidth 4 and buswidth 1.
[ 1.364979] m25p80 spi5.0: found n25q256a, expected m25p80
[ 1.370986] m25p80 spi5.0: n25q256a (32768 Kbytes)
[ 1.381020] m25p80 spi5.1: unrecognized JEDEC id bytes: ff, ff, ff
These are the DT settings:
&qspi1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_qspi1_1>;
status = "okay";
flash0: n25q256a@0 {
¦ #address-cells = <1>;
¦ #size-cells = <1>;
¦ compatible = "micron,m25p80";
¦ spi-max-frequency = <29000000>;
spi-rx-bus-width = <4>;
spi-tx-bus-width = <4>;
¦ reg = <0>;
};
flash1: n25q256a@1 {
¦ #address-cells = <1>;
¦ #size-cells = <1>;
¦ compatible = "micron,m25p80";
¦ spi-max-frequency = <29000000>;
spi-rx-bus-width = <4>;
spi-tx-bus-width = <4>;
¦ reg = <1>;
};
};
First, I think you should add "jedec,spi-nor" to your compatible properties.
Second, are you sure, that the two chips are both on QSPIA using the two
chip selects?
I have no schematics of the board, but if I look at the devicetree in
the linux-imx kernel [1] it seems to me that one chip is on QSPIA CS0
and the other on QSPIB CS0.
If this is the case, then you have to set reg = <2> for the second chip.
Thanks,
Frieder
[1]
http://git.freescale.com/git/cgit.cgi/imx/linux-imx.git/tree/arch/arm/boot/dts/imx6sx-sabreauto.dts?h=imx_4.9.11_1.0.0_ga#n771
Unrelated to this issue, we still have 2 questions left unanswered:
1/ is there an easy way to invalidate AHB buffers? I mean, not
something that implies a full reset + several milliseconds of delay
after the reset. Right now we trick the caching logic by mapping a
portion that is twice the size of the buffer and switching from one
sub-portion to this other to trigger a real read on each read
access, but that's hack-ish, and I'd be surprised if HW
engineers hadn't planned for this "manual AHB buffer flush" case.
2/ if we use DMA, do you know what happens when the TX FIFO runs out
of data while the TX request is not finished yet. In PIO mode, it
seems the engine sends garbage on the bus when that happens, and we
definitely don't want that.
While #1 is not blocking us, #2 is if we don't have those patches
[1][2] applied, and Marek wanted to be sure there was no other ways to
solve the "TX FIFO starvation" issue before considering these changes.
So that'd be great if someone from NXP could have a look/ask around
and give us answers to those 2 questions.
Thanks,
Boris
