Re: [PATCH] regmap: reject volatile update_bits() in cache-only mode

[Greg Kroah-Hartman]

On Thu, May 28, 2026 at 12:32:04PM +0700, phucduc.bui@xxxxxxxxx wrote:
> From: bui duc phuc <phucduc.bui@xxxxxxxxx>
> 
> Prevent _regmap_update_bits() from accessing hardware when the register
> map is in cache-only mode.
> 
> Unlike regmap_raw_read() and _regmap_read(), the volatile
> _regmap_update_bits() fast path bypasses the cache_only check. This can
> result in unexpected hardware accesses while the device is suspended.
> 
> Return -EBUSY to ensure behavior is consistent with other cache-only
> access paths.
> 
> Signed-off-by: bui duc phuc <phucduc.bui@xxxxxxxxx>
> ---
> 
> Compile-tested only.

So this isn't a real bug that you have found and tested this fix
resolves?  How was this "found"?

Please submit stuff that actually is verified to resolve a real issue.

thanks,

greg k-h