From: Sven Peter <sven@svenpeter.dev>
Date: Tue, 19 Oct 2021 18:22:53 +0200
Subject: iommu/dart: Initialize DART_STREAMS_ENABLE
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Git-commit: 5a009fc1364170b240a4d351b345e69bb3728b3e
Patch-mainline: v5.16-rc1
References: bsc#1205701
DART has an additional global register to control which streams are
isolated. This register is a bit redundant since DART_TCR can already
be used to control isolation and is usually initialized to DART_STREAM_ALL
by the time we get control. Some DARTs (namely the one used for the audio
controller) however have some streams disabled initially. Make sure those
work by initializing DART_STREAMS_ENABLE during reset.
Reported-by: Martin PoviĊĦer <povik@protonmail.com>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Reviewed-by: Hector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20211019162253.45919-1-sven@svenpeter.dev
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/apple-dart.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index 13ba258b7413..f0f4d1f74f92 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -70,6 +70,8 @@
#define DART_ERROR_ADDR_HI 0x54
#define DART_ERROR_ADDR_LO 0x50
+#define DART_STREAMS_ENABLE 0xfc
+
#define DART_TCR(sid) (0x100 + 4 * (sid))
#define DART_TCR_TRANSLATE_ENABLE BIT(7)
#define DART_TCR_BYPASS0_ENABLE BIT(8)
@@ -301,6 +303,9 @@ static int apple_dart_hw_reset(struct apple_dart *dart)
apple_dart_hw_disable_dma(&stream_map);
apple_dart_hw_clear_all_ttbrs(&stream_map);
+ /* enable all streams globally since TCR is used to control isolation */
+ writel(DART_STREAM_ALL, dart->regs + DART_STREAMS_ENABLE);
+
/* clear any pending errors before the interrupt is unmasked */
writel(readl(dart->regs + DART_ERROR), dart->regs + DART_ERROR);