resolve msc sdcard example conflict with host espcially macos

[hathach]

• use SDIO (pio) for rp2040/rp2350
• remove printing flash/sdcard contents to Serial since it conflict with host, which can cause conflict in spi/sdio transport and/or correupt cache,sector
• This "fix" completely remove the sdcard contents dump. a better fix would be marking the SDcard as not ready (return false in TEST_UNIT_READY) while performming self-reading, but that would maybe take a bit of time. I will do it later if needed.
• supercede and close macos support for msc #532 fix Mass Storage Controller microSD on Metro RP2040 #455

@mikeysklar let me know if this works for you (you need to update Sdfat to v2.3.50)

PS: The conflict happen with macos more often since macos does lots of hidden writing of meta data file e.g .DS_Store

[mikeysklar]

I'm not seeing the SD card on MacOS, but the flash continues to be shared successfullly. Just to confirm I'm running this PR's updated sketch and updated SdFat.

| Component                 | Version        |
|--------------------------|----------------|
| Operating System         | macOS Sequoia 15.5 |
| Arduino IDE              | 2.3.6          |
| Board                    | Adafruit Metro RP2040 |
| SdFat                    | 2.3.50         |
| Adafruit SPIFlash        | 5.1.1          |
| Adafruit TinyUSB Library | 3.6.0          |

I can dig more into what macOS thinks is going on.

Moving the same board to my Ubuntu laptop I see the microSD being shared. I can read / write files without issue.

sklarm@prego:/media/sklarm/SDCARD1$ df -H | grep sd..
/dev/sda1        16M   31k   16M   1% /media/sklarm/EXT FLASH
/dev/sdb1        16G  2.0M   16G   1% /media/sklarm/SDCARD1

[mikeysklar]

After removing power from the Metro RP2040 and bringing it back to macOS a working read/write auto-mounted microSD appeared. I'm guessing a hard reset is necessary since the board is correctly sharing the drive after being unplugged / replugged. I had been doing soft resets.

I did a quick drive test with a 10MB file going through the Metro RP2040 microSD and compared with with a directly connected (remove the controller and use a USB adapter). Probably what you expect to see. Read speed is crazy fast, but that must be caching so not a fair comparison.

| Access Method                 | Write Speed | Read Speed    | Write Gain |
|------------------------------|-------------|---------------|------------|
| RP2040 (mounted via USB MSC) | 0.72 MB/s   | 1.24 MB/s     | 1×         |
| USB-C Adapter (macOS)        | 4.59 MB/s   | 4666.04 MB/s* | ~6.4×      |

[hathach]

Great, thank you for testing.

you can try usign the old SPI by comment out the SDIO_CMD/CLK/DATA_PIN and define the SDCARD_CS to see if the speed is actual improved using new SDIO (pio)

[mikeysklar]

I disabled SDIO and gave SPI a try. That was a good test.

SPI is 6x slower than SDIO
SDIO is 6x slower than direct connect.

| Access Method           | Write Speed | Read Speed    | Write Gain |
|-------------------------|-------------|---------------|------------|
| RP2040 SPI MSC          | 0.11 MB/s   | 0.43 MB/s     | 1×         |
| RP2040 SDIO MSC         | 0.72 MB/s   | 1.24 MB/s     | ~6.5×      |
| USB-C Adapter (macOS)   | 4.59 MB/s   | 4666.04 MB/s* | ~42×       |

[hathach]

Card reader is usb highspeed while rp2040 is full speed 12 Mbit/s i.e 1.5 MB/s so 1.25Mbyte is as good as you can get. I think we can merge this now. Thank you very much for your effort to try and test this issue

@ladyada we get at least 3x for sdcard using pio as sdio. Note that somehow I cannot get metro rp2350 working with it. Maybe I miss some settings, will try to fix it next week

[ladyada]

hmm it should work but to be honest we didn't try it, do you want to buy https://www.adafruit.com/product/4682 and try wiring it up to any other pins

[hathach]

yeah, not sure why, will test it further, and make an PR to fix later.

[hathach]

@ladyada I used an exterrnal sdcard breakout with pin 22,23,8,9,10,11 and it seems to work well. I think the upstream SdFat currently does not support GPIO that is larger than 31/32

https://github.com/greiman/SdFat/blob/a4ecec60554e8071e3f15a4407cad3908519c06e/src/SdCard/Rp2040Sdio/PioSdioCard.cpp#L329-L330

  g_pio->input_sync_bypass |=
      (1 << g_clkPin) | (1 << g_cmdPin) | (0XF << g_dat0Pin);

I will file an issue and try to see if we can make a PR to upstream

[hathach]

@ladyada once I have manage to fix the GPIO > 32 issue with adafruit/SdFat#35, I just realize that upstream just fixed it a few days ago, though it is pushed to SdFat-beta repo greiman/SdFat-beta@e8208b1 which is scheduled to release as 2.3.1 soon. Instead of waiting, I think we can just go ahead and merge with SdFat-beta for now and do the sync later on if there is any other commit.

[ladyada]

yes please! thank you :)

[hathach]

update: I am backing off from SdFat-beta, since there is lots of refactor and rename, which is time-consuming to cherry pick and re-sync. It is probably faster to apply simple fix in adafruit/SdFat#35 and do simple sync/merge with upstream later :)

[ladyada]

thats fine

[hathach]

https://github.com/adafruit/SdFat/releases/tag/2.3.53 is released and fixed issue with high GPIO for now, we will sync with upstream when it is released later.

[mikeysklar]

I had the opportunity to do an updated read / write test using the RP2350 changes @hathach has recently made to the Adafruit SdFat. I tried using my fastest microSD.

| Component                 | Version/Details           |
|--------------------------|---------------------------|
| Operating System         | macOS Sequoia 15.5        |
| Arduino IDE              | 2.3.6                     |
| Board                    | Adafruit Metro RP2350     |
| BSP (Philhower)          | 4.5.4                     |
| SdFat Library            | Adafruit Fork 2.3.53      |
| Adafruit SPIFlash        | 5.1.1                     |
| Adafruit TinyUSB Library | 3.6.1                     |
| microSD Card             | PNY A1, U3, V30           |

| Access Method           | Write Speed | Read Speed     | Write Gain |
|-------------------------|-------------|----------------|------------|
| USB-C Adapter (macOS)   | 18.44 MB/s  | 5102.56 MB/s*  | ~168×      |
| RP2350 SDIO MSC         | 0.81 MB/s   | 1.62 MB/s      | ~7.4×      |
| RP2040 SDIO MSC         | 0.72 MB/s   | 1.24 MB/s      | ~6.5×      |
| RP2040 SPI MSC          | 0.11 MB/s   | 0.43 MB/s      | 1×         |

[hathach]

superb! thank you @mikeysklar for detail testing.

[ladyada]

yay thanks for the thorough test. cc @caternuson ^