Issue: USB MSC with FATFS on nRF54H20 External Flash (Write Error & SCSI Opcode 0xa1)

[kile.gc]

Description: I am implementing USB Mass Storage with a FAT filesystem on external MX25UW63 flash (via EXMIF) using the nRF54H20 DK (NCS v3.2.0).

Setup:

• Board: nRF54H20 DK

• SDK: nRF Connect SDK v3.2.0

• Reference: zephyr/samples/subsys/usb/mass

Configuration:

nrf54h20dk_nrf54h20_cpuapp.overlay:

/delete-node/ &storage_partition;

&exmif {
	status = "okay";
};

&gpio6 {
	status = "okay";
};

&mx25uw63 {
	status = "okay";

    partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		storage_partition: partition@0 {
			label = "storage";
			reg = <0x00000000 0x00020000>;
		};
	};
};

/ {
	msc_disk0 {
		compatible = "zephyr,flash-disk";
		partition = <&storage_partition>;
		disk-name = "NAND";
		cache-size = <4096>;
	};
};

nrf54h20dk_nrf54h20_cpuapp.conf:

CONFIG_APP_MSC_STORAGE_FLASH_FATFS=y

Error Log:

*** Booting nRF Connect SDK v3.2.0-5dcc6bd39b0f ***
*** Using Zephyr OS v4.2.99-a57ad913cf4e ***
Area 0 at 0x0 on mx25uw6345g@0 for 131072 bytes
[00:00:00.024,795] <inf> flashdisk: Initialize device NAND
[00:00:00.024,800] <inf> flashdisk: offset 0, sector size 512, page size 65536, volume size 131072
[00:00:00.024,806] <err> flashdisk: Cache too small (4096 needs 65536)
[00:00:00.024,812] <err> fs: fs mount error (-5)
[00:00:00.024,816] <err> main: Failed to mount filesystem
[00:00:00.024,915] <wrn> udc_dwc2: VBUS is not ready, block udc_enable()
[00:00:00.060,241] <wrn> udc_dwc2: Experimental DMA enabled
[00:00:00.060,287] <inf> main: The device is put in USB mass storage mode
[00:00:00.403,512] <inf> usbd_msc: Enable
[00:00:00.403,577] <inf> usbd_msc: Bulk-Only Mass Storage Reset
[00:00:01.456,398] <err> usbd_msc: Unknown SCSI opcode 0xa1

Current Status:

I initially had a cache error, which I resolved by increasing the cache size to 65536. However, I am now facing two issues:

1. Write Failure: When I try to create a file on the disk, the operation fails with the following log:

   [INSERT FILE CREATION ERROR LOG HERE]
   

2. SCSI Error: I also see this error in the logs:

   [00:00:01.594,387] <err> usbd_msc: Unknown SCSI opcode 0xa1
   

Questions:

• What could be causing the file creation/write failure?

• What does Unknown SCSI opcode 0xa1 mean in this context? Is it critical?

Any advice is appreciated.

[Simonr]

Hi

1. Do you have the full log of what you're currently seeing when trying to write so I can get some more context? It looks like you didn't add the file creation error log you meant to.

2. I believe that the 0xa1 opcode refers to blank or "passthrough", depending on what function/command you have called with SCSI. It does not seem critical, so I think we should focus on the write failure first and take it from there.

Best regards,

Simon

[kile.gc]

Hi Simon,

Sorry for not including the error evidence earlier - DevZone went into maintenance and I might forgot to add it. Let me start fresh.

With cache size 4096: The filesystem fails to mount (see attached). I'm unsure if this is a flash or exmif interface issue.


With cache size 63356: The mount error disappears. I checked dropped messages - nothing unusual.


File creation issue: When I create a file from OS I get no logs at all (see attached). but I got the error from OS.

This is when I created a file in vscode.



I didn't get any log from nRF54H20 when I created a file.

Questions:

- Why would 4096 fail while 63356 works?
- Are there any debug configs I should enable to see file operations and troubleshoot this?

Thanks for your help!