bus: mvebu-mbus: fix support of MBus window 13

commit 38bdf45f4aa5cb6186d50a29e6cbbd9d486a1519 upstream. On Armada XP, 375 and 38x the MBus window 13 has the remap capability, like windows 0 to 7. However, the mvebu-mbus driver isn't currently taking into account this special case, which means that when window 13 is actually used, the remap registers are left to 0, making the device using this MBus window unavailable. As a minimal fix for stable, don't use window 13. A full fix will follow later. Fixes: fddddb52a6c ("bus: introduce an Marvell EBU MBus driver") Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

bus: mvebu-mbus: fix support of MBus window 13
commit 38bdf45f4aa5cb6186d50a29e6cbbd9d486a1519 upstream. On Armada XP, 375 and 38x the MBus window 13 has the remap capability, like windows 0 to 7. However, the mvebu-mbus driver isn't currently taking into account this special case, which means that when window 13 is actually used, the remap registers are left to 0, making the device using this MBus window unavailable. As a minimal fix for stable, don't use window 13. A full fix will follow later. Fixes: fddddb52a6c ("bus: introduce an Marvell EBU MBus driver") Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Andrew Lunn · Greg Kroah-Hartman
1 parent e3143069ec
Showing 1 changed file with 13 additions and 0 deletions Side-by-side Diff
drivers/bus/mvebu-mbus.c
@@ -181,12 +181,25 @@
 }
  
 /* Checks whether the given window number is available */
+
+/* On Armada XP, 375 and 38x the MBus window 13 has the remap
+ * capability, like windows 0 to 7. However, the mvebu-mbus driver
+ * isn't currently taking into account this special case, which means
+ * that when window 13 is actually used, the remap registers are left
+ * to 0, making the device using this MBus window unavailable. The
+ * quick fix for stable is to not use window 13. A follow up patch
+ * will correctly handle this window.
+*/
 static int mvebu_mbus_window_is_free(struct mvebu_mbus_state *mbus,
 				     const int win)
 {
 	void __iomem *addr = mbus->mbuswins_base +
 		mbus->soc->win_cfg_offset(win);
 	u32 ctrl = readl(addr + WIN_CTRL_OFF);
+
+	if (win == 13)
+		return false;
+
 	return !(ctrl & WIN_CTRL_ENABLE);
 }
...	...	@@ -181,12 +181,25 @@
181	181	}
182	182
183	183	/* Checks whether the given window number is available */
	184	+
	185	+/* On Armada XP, 375 and 38x the MBus window 13 has the remap
	186	+ * capability, like windows 0 to 7. However, the mvebu-mbus driver
	187	+ * isn't currently taking into account this special case, which means
	188	+ * that when window 13 is actually used, the remap registers are left
	189	+ * to 0, making the device using this MBus window unavailable. The
	190	+ * quick fix for stable is to not use window 13. A follow up patch
	191	+ * will correctly handle this window.
	192	+*/
184	193	static int mvebu_mbus_window_is_free(struct mvebu_mbus_state *mbus,
185	194	const int win)
186	195	{
187	196	void __iomem *addr = mbus->mbuswins_base +
188	197	mbus->soc->win_cfg_offset(win);
189	198	u32 ctrl = readl(addr + WIN_CTRL_OFF);
	199	+
	200	+ if (win == 13)
	201	+ return false;
	202	+
190	203	return !(ctrl & WIN_CTRL_ENABLE);
191	204	}
192	205