[PATCH] docs: driver-api: firmware: clarify userspace requirements

[Jacek Lawrynowicz]

The guidelines mention that firmware updates can't break the kernel,
but it doesn't state directly that they can't break userspace programs.
Make it explicit that firmware updates cannot break UAPI.

Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz at linux.intel.com>
---
 .../driver-api/firmware/firmware-usage-guidelines.rst        | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/driver-api/firmware/firmware-usage-guidelines.rst b/Documentation/driver-api/firmware/firmware-usage-guidelines.rst
index fdcfce42c6d28..5f8f13e2ee510 100644
--- a/Documentation/driver-api/firmware/firmware-usage-guidelines.rst
+++ b/Documentation/driver-api/firmware/firmware-usage-guidelines.rst
@@ -42,3 +42,8 @@ then of course these rules will not apply strictly.)
   deprecating old major versions, then this should only be done as a
   last option, and be stated clearly in all communications.
 
+* Firmware files that affect the User API (UAPI) shall not introduce
+  changes that break existing userspace programs. Updates to such firmware
+  must ensure backward compatibility with existing userspace applications.
+  This includes maintaining consistent interfaces and behaviors that
+  userspace programs rely on.
\ No newline at end of file
-- 
2.45.1