Regression: at24 eeprom writing times out on sama5d3

Codrin.Ciubotariu at microchip.com Codrin.Ciubotariu at microchip.com
Fri Jun 10 00:35:00 PDT 2022


On 09.06.2022 17:28, Peter Rosin wrote:
> Hi!

Hi Peter,

> 
> 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.
> 
> 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 8160 --> 0 (753885)

could you please apply this patch-set [1] and let us know if it 
addresses your issue?

Thanks and best regards,
Codrin

https://patchwork.ozlabs.org/project/linux-i2c/list/?series=255408


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