Hi Antoine,

I would like to add this small patch to make my scanner Canon PIXMA
MG3250 work with the SCAN button.

See:

- https://gitlab.com/sane-project/backends/-/work_items/856
- https://gitlab.com/sane-project/backends/-/merge_requests/933


Index: Makefile
===================================================================
RCS file: /cvs/ports/graphics/sane-backends/Makefile,v
diff -u -p -u -r1.118 Makefile
--- Makefile	1 Nov 2025 11:16:41 -0000	1.118
+++ Makefile	8 Jul 2026 10:02:31 -0000
@@ -3,7 +3,7 @@ BROKEN-alpha=		ICE hp5590.c:1141: error:
 COMMENT=		API for accessing scanners, backends
 
 V=			1.4.0
-REVISION=		2
+REVISION=		3
 DISTNAME=		backends-${V}
 PKGNAME=		sane-${DISTNAME}
 
Index: patches/patch-backend_pixma_pixma_mp150_c
===================================================================
RCS file: patches/patch-backend_pixma_pixma_mp150_c
diff -N patches/patch-backend_pixma_pixma_mp150_c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ patches/patch-backend_pixma_pixma_mp150_c	8 Jul 2026 10:02:31 -0000
@@ -0,0 +1,30 @@
+PIXMA: decode SCAN button interrupt on MG3200 series (buf[4])
+
+- https://gitlab.com/sane-project/backends/-/work_items/856
+- https://gitlab.com/sane-project/backends/-/merge_requests/933
+
+Index: backend/pixma/pixma_mp150.c
+--- backend/pixma/pixma_mp150.c.orig
++++ backend/pixma/pixma_mp150.c
+@@ -1049,6 +1049,21 @@ handle_interrupt (pixma_t * s, int timeout)
+       s->events = PIXMA_EV_BUTTON1 | (buf[0x13] & 0x0f);
+     }
+   }
++  else if (s->cfg->pid == MG3200_PID)
++  /* MG3200 series: SCAN is the only button reported; flag in buf[4].
++   * buf[3] & 1 is a clock request as in the default branch. */
++  {
++    if (buf[3] & 1)
++      /* FIXME: This function makes trouble with a lot of scanners
++      send_time (s);
++       */
++      PDBG (pixma_dbg (1, "WARNING:send_time() disabled!\n"));
++    if (buf[4] & 1)
++    {
++      /* start scan */
++      s->events = PIXMA_EV_BUTTON1;
++    }
++  }
+   else
+   /* button no. in buf[0]
+    * original in buf[0]

-- 
Regards,
 Mikolaj