[U-Boot] [PULL] Please pull u-boot-imx

Baruch Siach baruch at tkos.co.il
Mon Nov 19 07:44:09 UTC 2018 

Hi Ricardo,

On Sun, Nov 18, 2018 at 05:43:02PM -0200, Ricardo Salveti wrote:
> On Sun, Nov 18, 2018 at 7:51 AM Baruch Siach <baruch at tkos.co.il> wrote:
> > Peter Robinson writes:
> > > On Fri, Nov 16, 2018 at 1:06 AM Ricardo Salveti <rsalveti at rsalveti.net> wrote:
> > >> On Wed, Nov 14, 2018 at 5:07 AM Baruch Siach <baruch at tkos.co.il> wrote:
> > >> > On Tue, Nov 13, 2018 at 11:42:44AM -0200, Ricardo Salveti wrote:
> > >> > > On Thu, Sep 6, 2018 at 12:52 PM Fabio Estevam <festevam at gmail.com> wrote:
> > >> > > > On Thu, Sep 6, 2018 at 12:42 PM, Baruch Siach <baruch at tkos.co.il> wrote:
> > >> > > >
> > >> > > > > I tested current master successfully on Hummingboard2 with i.MX6 Solo
> > >> > > > > (SOM rev 1.5):
> > >> > > >
> > >> > > > Thanks for testing.
> > >> > > >
> > >> > > > It seems we need more information from Peter about the regression he reported.
> > >> > > >
> > >> > > > It would be helpful if Peter could run a bisect so that we could
> > >> > > > understand where the regression is coming from.
> > >> > >
> > >> > > Finally got the time to test u-boot 2018.09 on my hummingboard 2 and I
> > >> > > can also confirm the boot issue with imx6q (Hummingboard 2 MicroSOM
> > >> > > i2eX iMX6D - rev 1.3).
> > >> > >
> > >> > > The patch set that introduced this regression was part of another pull
> > >> > > request, the one that introduces eMMC booting support (from Jon
> > >> > > Nettleton, e.g. 86e5a7fc13 and 19ed6063a5). After doing some more
> > >> > > testing it seems that the hang happens when trying to verify if the
> > >> > > board has eMMC during runtime (has_emmc -> mmc_get_op_cond(mmc)),
> > >> > > which is not the case for this SOM in particular (and probably why it
> > >> > > works fine on most rev 1.5-based SOMs, as eMMC is usually available
> > >> > > there).
> > >> > >
> > >> > > Tested with current u-boot master and the issue is still valid.
> > >> > >
> > >> > > Jon, did you have any issue when testing that patch set on SOMs
> > >> > > without eMMC support?
> > >> >
> > >> > I tested U-Boot successfully with SOM rev 1.3 (no eMMC) on Hummingboard2, as
> > >> > shown in my previous message on this thread.
> > >>
> > >> Indeed, you tested with i.MX6Q, only difference is that mine is iMX6D,
> > >> but both without eMMC.
> > >
> > > I see the issue with a .IMX6Q wirth SOM rev 1.5 (TI wifi, no EMMC) on
> > > a hummingboard2
> >
> > I could not reproduce with SOM rev 1.3 (no eMMC) on Hummingboard2.
> >
> > >> > What toolchain are you using?
> > >>
> > >> Using GCC 8.2 from latest OpenEmbedded. Will try building with the
> > >> version you used to see if I get any different behavior.
> > >
> > > gcc 8.2.x from Fedora 29
> >
> > I am using the ARM (Ltd) provided GNU toolchain version 8.2:
> >
> > => version
> > U-Boot 2018.11 (Nov 18 2018 - 11:22:16 +0200)
> >
> > arm-linux-gnueabihf-gcc (GNU Toolchain for the A-profile Architecture 8.2-2018-08 (arm-rel-8.23)) 8.2.1 20180802
> > GNU ld (GNU Toolchain for the A-profile Architecture 8.2-2018-08 (arm-rel-8.23)) 2.30.0.20180625
> >
> > >> > What do you see on the serial console?
> > >>
> > >> It boots up to the point when it tries to find the emmc, and then it
> > >> basically hangs completely (tested with current master):
> > >>
> > >> U-Boot SPL 2018.11+gf6206f8587 (Nov 16 2018 - 00:56:34 +0000)
> > >> Trying to boot from MMC1
> > >>
> > >> U-Boot 2018.11+gf6206f8587 (Nov 16 2018 - 00:56:34 +0000)
> > >>
> > >> CPU:   Freescale i.MX6D rev1.5 996 MHz (running at 792 MHz)
> > >> CPU:   Extended Commercial temperature grade (-20C to 105C) at 33C
> > >> Reset cause: POR
> > >> Board: MX6 HummingBoard2
> > >> DRAM:  1 GiB
> > >> MMC:   FSL_SDHC: 0, FSL_SDHC: 1
> > >> Loading Environment from MMC... *** Warning - bad CRC, using default environment
> > >>
> > >> No panel detected: default to HDMI
> > >> Display: HDMI (1024x768)
> > >> In:    serial
> > >> Out:   serial
> > >> Err:   serial
> > >> ---> hangs
> > >
> > > Exactly the same as I saw.
> >
> > Here is what I get at this point:
> >
> > In:    serial
> > Out:   serial
> > Err:   serial
> > Card did not respond to voltage select!
> > Net:   FEC
> > ...
> >
> > The error message is from drivers/mmc/mmc.c:mmc_get_op_cond(). The code
> > around this point might be the source of your issue. Can you add a few
> > prints in mmc_get_op_cond() to pinpoint the call that hangs the code?
> 
> Also tried with ARM's pre-built toolchain (same version), and got the
> same hang. Looking a bit further, it basically looks up while waiting
> the first mmc command to complete:
> 
> has_emmc -> mmc_get_op_cond -> mmc_send_if_cond (testing for SD
> version 2) -> mmc_send_cmd -> esdhc_send_cmd_common -> while
> (!(esdhc_read32(&regs->irqstat) & flags))
> 
> And the boot log with MMC_TRACE:
> 
> No panel detected: default to HDMI
> Display: HDMI (1024x768)
> In:    serial
> Out:   serial
> Err:   serial
> CMD_SEND:0
>                 ARG                      0x00000000
>                 MMC_RSP_NONE
> CMD_SEND:8
>                 ARG                      0x000001AA
> 
> The line where it locks up waiting for the command to complete:
> http://git.denx.de/?p=u-boot.git;a=blob;f=drivers/mmc/fsl_esdhc.c;h=3cdfa7f5a689789ea2f24da867d7c947ab78c002;hb=HEAD#l455
> 
> Unclear why this only happens with this som/soc, maybe hardware/errata
> differences?

Here's what I get after adding irqstat print:

CMD_SEND:0
		ARG			 0x00000000
		MMC_RSP_NONE
CMD_SEND:8
		ARG			 0x000001AA
esdhc_send_cmd_common: irqstat: 10000
		RET			 -110

The irqstat register has the DTOE (Data Timeout Error) bit enabled right after 
the irqstat wait loop that hangs in your setup.

I guess Fabio's patch would fix the issue for you. Indefinite loops are not a 
good idea in general, I think.

baruch

-- 
     http://baruch.siach.name/blog/                  ~. .~   Tk Open Systems
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