topic Re: IMX8QM LPI2C DMA error in i.MX Processors

IMX8QM LPI2C DMA error

mohamedmusthafa — Tue, 07 Sep 2021 10:15:25 GMT

Hi,

i get the following kernel logs for i2c in imx8qm, we are using 5.10.35 version linux kernel

root@:~# dmesg | grep i2c
[ 2.379560] i2c /dev entries driver
[ 2.994049] imx-lpi2c 3b230000.i2c: can't get the TX DMA channel, error -19!
[ 3.001120] imx-lpi2c 3b230000.i2c: error -ENODEV: dma setup error -19, use pio
[ 3.053200] i2c i2c-2: LPI2C adapter registered
[ 3.058640] imx-lpi2c 5a800000.i2c: can't get the TX DMA channel, error -19!
[ 3.065727] imx-lpi2c 5a800000.i2c: error -ENODEV: dma setup error -19, use pio
[ 9.683160] i2c i2c-3: LPI2C adapter registered
[ 9.697523] imx-lpi2c 5a810000.i2c: using scl,sda for recovery
[ 9.703374] imx-lpi2c 5a810000.i2c: can't get the TX DMA channel, error -19!
[ 9.710438] imx-lpi2c 5a810000.i2c: error -ENODEV: dma setup error -19, use pio
[ 9.953716] i2c i2c-4: LPI2C adapter registered
[ 9.959539] imx-lpi2c 58226000.i2c: can't get the TX DMA channel, error -19!
[ 9.966609] imx-lpi2c 58226000.i2c: error -ENODEV: dma setup error -19, use pio
[ 10.299223] i2c i2c-5: LPI2C adapter registered
[ 10.305256] imx-lpi2c 58246000.i2c: can't get the TX DMA channel, error -19!
[ 10.312363] imx-lpi2c 58246000.i2c: error -ENODEV: dma setup error -19, use pio
[ 10.342772] i2c i2c-6: LPI2C adapter registered
[ 10.759768] imx-lpi2c 56247000.i2c: can't get the TX DMA channel, error -19!
[ 10.766862] imx-lpi2c 56247000.i2c: error -ENODEV: dma setup error -19, use pio
[ 10.782481] i2c i2c-7: LPI2C adapter registered
[ 10.787813] imx-lpi2c 57247000.i2c: can't get the TX DMA channel, error -19!
[ 10.794886] imx-lpi2c 57247000.i2c: error -ENODEV: dma setup error -19, use pio
[ 11.817094] i2c i2c-8: LPI2C adapter registered
[ 11.824084] imx-lpi2c 56226000.i2c: can't get the TX DMA channel, error -19!
[ 11.831167] imx-lpi2c 56226000.i2c: error -ENODEV: dma setup error -19, use pio
[ 11.887837] i2c i2c-9: LPI2C adapter registered
[ 11.893251] imx-lpi2c 57226000.i2c: can't get the TX DMA channel, error -19!
[ 11.900325] imx-lpi2c 57226000.i2c: error -ENODEV: dma setup error -19, use pio
[ 11.957434] i2c i2c-10: LPI2C adapter registered
root@:~#

it uses pio instead of DMA

how can we enable DMA transfer mode?

Thanks & Regards,

mohamed

Re: IMX8QM LPI2C DMA error

igorpadykov — Wed, 08 Sep 2021 00:36:39 GMT

Hi Mohamed

not all i2c have dma supported as described in datasheet

i.MX 8QuadMax Automotive and Infotainment Applications Processors

Best regards
igor

Re: IMX8QM LPI2C DMA error

mohamedmusthafa — Wed, 08 Sep 2021 11:15:55 GMT

Hi,

We Are using M41_I2C0_SCL , M41_I2C0_SDA to connect EEPROM in our custom board.

the above mentioned logs are getting for custom board based on iMX8QM processor.

but in mek we are not getting error like that ,please find the below log in mek

we are using i2c-2 bus, which is the device tree node for M4 I2C

root@dictgu:~# dmesg | grep i2c
[ 2.026260] i2c /dev entries driver
[ 3.092767] i2c i2c-2: LPI2C adapter registered
[ 3.125138] input: fxos8700 as /devices/platform/bus@5a000000/5a800000.i2c/i2c-3/3-001e/input/input2
[ 3.136865] input: fxas2100x as /devices/platform/bus@5a000000/5a800000.i2c/i2c-3/3-0020/input/input3
[ 3.179499] OF: graph: no port node found in /bus@5a000000/i2c@5a800000/tcpc@51
[ 3.192181] i2c i2c-3: LPI2C adapter registered
[ 3.206233] imx-lpi2c 5a810000.i2c: using scl,sda for recovery
[ 3.216089] i2c i2c-4: LPI2C adapter registered
[ 3.244320] i2c i2c-5: LPI2C adapter registered
[ 3.272327] i2c i2c-6: LPI2C adapter registered
[ 3.277391] imx-lpi2c 56247000.i2c: can't get irq number
[ 3.283445] imx-lpi2c 57247000.i2c: can't get irq number
[ 3.289465] imx-lpi2c 56226000.i2c: can't get irq number
[ 3.295484] imx-lpi2c 57226000.i2c: can't get irq number
[ 4.216360] OF: graph: no port node found in /bus@5a000000/i2c@5a800000/tcpc@51
[ 4.239025] i2c i2c-7: LPI2C adapter registered
[ 4.251672] i2c i2c-8: LPI2C adapter registered
[ 4.309271] i2c i2c-9: LPI2C adapter registered
[ 4.402626] i2c i2c-10: LPI2C adapter registered
[ 4.536002] debugfs: Directory 'mipi1-i2c1' with parent 'pm_genpd' already present!
[ 4.543710] debugfs: Directory 'mipi1-i2c0' with parent 'pm_genpd' already present!
root@dictgu:~#

Re: IMX8QM LPI2C DMA error

igorpadykov — Wed, 08 Sep 2021 13:47:19 GMT

if it works on MEK board you can try to debug it using AN12631: Normal and Secure Debug for i.MX8/8X Family of Applications Processors – Application Note

and running the same image on both boards.

Best regards
igor