MSC - how to tell HOST is done writing?

[gmikitiuk]

Hello,

I'm new to MSC and I'm wondering if it's possible to detect that HOST has finished writing(so I can check for file moditifations and take respective actions?).

Any hints highly appreciated.

[hathach]

there is a risk for race condition, host can just write data at anytime even if you check is it not now, it can write when you start or in the middle of flashing. The way to do this is:

• implement tud_msc_is_writable_cb() to return false when you want to modify the flash: that will cause tinyusb to reject and write atempt by host (making it read-only temporary)
• to sync the is_writable, you wait for tud_msc_write10_complete_cb() and set is_writable to false there, which can prevent changing to read-only in the middle of writing (confusing host).

Note: after local modifed, the data won't be updated by host, host has comprehensive data caching (both read/write). I forgot the detail, but i think you can find approach somewhere in the dicussion/issue.

[gmikitiuk]

Thanks I will proceed with this approach