[PATCH 5/7] soundwire: clarify maximum allowed address

From: Bard Liao
Date: Tue Mar 26 2024 - 05:02:53 EST


From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Reviewed-by: Rander Wang <rander.wang@xxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
include/linux/soundwire/sdw_registers.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/soundwire/sdw_registers.h b/include/linux/soundwire/sdw_registers.h
index 138bec908c40..658b10fa5b20 100644
--- 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
--
2.34.1