Re: Regression: at24 eeprom writing times out on sama5d3

From: Thorsten Leemhuis
Date: Sat Jun 11 2022 - 09:41:50 EST


[TLDR: I'm adding this regression report to the list of tracked
regressions; all text from me you find below is based on a few templates
paragraphs you might have encountered already already in similar form.]

Hi, this is your Linux kernel regression tracker.

On 09.06.22 16:28, Peter Rosin wrote:
> Hi!
>
> I have not actually bisected this issue but reverting the effects of
> patch a4bd8da893a3 ("ARM: dts: at91: sama5d3: add i2c gpio pinctrl")
> makes the problem go away.

To be sure below issue doesn't fall through the cracks unnoticed, I'm
adding it to regzbot, my Linux kernel regression tracking bot:

#regzbot ^introduced a4bd8da893a3
#regzbot title i2c: at24 eeprom writing times out on sama5d3
#regzbot ignore-activity
#regzbot monitor:
https://lore.kernel.org/all/20210727111554.1338832-1-codrin.ciubotariu@xxxxxxxxxxxxx/

This isn't a regression? This issue or a fix for it are already
discussed somewhere else? It was fixed already? You want to clarify when
the regression started to happen? Or point out I got the title or
something else totally wrong? Then just reply -- ideally with also
telling regzbot about it, as explained here:
https://linux-regtracking.leemhuis.info/tracked-regression/

Reminder for developers: When fixing the issue, add 'Link:' tags
pointing to the report (the mail this one replied to), as the kernel's
documentation call for; above page explains why this is important for
tracked regressions.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.



> I.e. I need something like this in my dts
>
> &i2c2 {
> status = "okay";
>
> pinctrl-names = "default";
> /delete-property/ pinctrl-1;
> /delete-property/ sda-gpios;
> /delete-property/ scl-gpios;
>
> eeprom@50 {
> compatible = "st,24c64", "atmel,24c64";
> reg = <0x50>;
> wp-gpios = <&filter_gpio 7 GPIO_ACTIVE_HIGH>;
> };
> };
>
> for multi-page eeprom writes to not time out (a page is 32 bytes on this
> eeprom).
>
> For reference, the current defaults for this SoC/I2C-bus, that I modify,
> are:
>
> pinctrl-names = "default", "gpio";
> pinctrl-0 = <&pinctrl_i2c2>;
> pinctrl-1 = <&pinctrl_i2c2_gpio>;
> sda-gpios = <&pioA 18 GPIO_ACTIVE_HIGH>;
> scl-gpios = <&pioA 19 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
>
> I suspect that the underlying reason is that the bus recovery takes
> too long and that the at24 eeprom driver gives up prematurely. I doubt
> that this is chip specific, but I don't know that.
>
> I can work around the issue in user space with by writing in 4 byte
> chunks, like so
>
> dd if=source.file of=/sys/bus/i2c/devices/2-0050/eeprom obs=4
>
> but that is really ugly and gets slow too, about 20 seconds to program
> the full 8kB eeprom. With the above in my dts it takes a second or
> so (a bit more with dynamic debug active).
>
>
> If I run
>
> dd if=source.file of=/sys/bus/i2c/devices/2-0050/eeprom
>
> with a source.file of 8kB and the upstream dts properties in place, I can
> collect the following debug output from at24, i2c-core and i2c-at91:
>
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:56:34 me20 kernel: at24 2-0050: write 32@0 --> 0 (-23170)
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: received nack
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: Trying i2c bus recovery
> Jun 9 15:56:34 me20 kernel: at24 2-0050: write 32@32 --> -121 (-23169)
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:56:34 me20 kernel: at24 2-0050: write 32@32 --> 0 (-23168)
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: received nack
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: Trying i2c bus recovery
> Jun 9 15:56:34 me20 kernel: at24 2-0050: write 32@64 --> -121 (-23168)
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:56:34 me20 kernel: at24 2-0050: write 32@64 --> 0 (-23167)
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: received nack
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: Trying i2c bus recovery
> Jun 9 15:56:34 me20 kernel: at24 2-0050: write 32@96 --> -121 (-23167)
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: controller timed out
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: Trying i2c bus recovery
> Jun 9 15:56:34 me20 kernel: at24 2-0050: write 32@96 --> -110 (-23155)
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:56:34 me20 kernel: at91_i2c f801c000.i2c: controller timed out
> Jun 9 15:56:34 me20 kernel: i2c i2c-2: Trying i2c bus recovery
> Jun 9 15:56:34 me20 kernel: at24 2-0050: write 32@96 --> -110 (-23143)
>
> And then there is no more action. I.e. only a couple of 32 byte pages
> are written.
>
> With the above mentioned dts override in place I instead get this, which is
> a lot more sensible:
>
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@0 --> 0 (753629)
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: received nack
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@32 --> -121 (753629)
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@32 --> 0 (753630)
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: received nack
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@64 --> -121 (753630)
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@64 --> 0 (753631)
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: received nack
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@96 --> -121 (753631)
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@96 --> 0 (753632)
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: received nack
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@128 --> -121 (753632)
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@128 --> 0 (753633)
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: received nack
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@160 --> -121 (753633)
> Jun 9 15:48:53 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:53 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:48:53 me20 kernel: at24 2-0050: write 32@160 --> 0 (753634)
> ... snip ...
> Jun 9 15:48:55 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:55 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:55 me20 kernel: at91_i2c f801c000.i2c: received nack
> Jun 9 15:48:55 me20 kernel: at24 2-0050: write 32@8128 --> -121 (753883)
> Jun 9 15:48:55 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:55 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:55 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:48:55 me20 kernel: at24 2-0050: write 32@8128 --> 0 (753884)
> Jun 9 15:48:55 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:55 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:55 me20 kernel: at91_i2c f801c000.i2c: received nack
> Jun 9 15:48:55 me20 kernel: at24 2-0050: write 32@8160 --> -121 (753884)
> Jun 9 15:48:55 me20 kernel: i2c i2c-2: at91_xfer: processing 1 messages:
> Jun 9 15:48:55 me20 kernel: at91_i2c f801c000.i2c: transfer: write 34 bytes.
> Jun 9 15:48:55 me20 kernel: at91_i2c f801c000.i2c: transfer complete
> Jun 9 15:48:55 me20 kernel: at24 2-0050: write 32@8160 --> 0 (753885)
>
> Cheers,
> Peter