soundwire: clarify maximum allowed address

The existing code sets the maximum address at 0x80000000, which is not
completely accurate. The last 2 Gbytes are indeed reserved, but so are
the 896 Mbytes just before. The maximum address which can be used with
paging or BRA is 0x47FFFFFF per Table 131 of the SoundWire 1.2.1
specification.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20240326090122.1051806-6-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/include/linux/soundwire/sdw_registers.h b/include/linux/soundwire/sdw_registers.h
index 138bec908c40c590269ca7faf4a6ff8688e9223b..658b10fa5b20adb2babbf9c5694696d5044fefe3 100644 (file)
--- a/include/linux/soundwire/sdw_registers.h
+++ b/include/linux/soundwire/sdw_registers.h
@@ -13,7 +13,7 @@
 
 #define SDW_REG_NO_PAGE                                0x00008000
 #define SDW_REG_OPTIONAL_PAGE                  0x00010000
-#define SDW_REG_MAX                            0x80000000
+#define SDW_REG_MAX                            0x48000000
 
 #define SDW_DPN_SIZE                           0x100
 #define SDW_BANK1_OFFSET                       0x10