[PATCH v2] dmaengine: mmp_pdma: fix wrong extended DRCMR base for SpacemiT K3

[Troy Mitchell]

The extended DRCMR window on SpacemiT K3 starts at 0x1100. Commit
6587b8661a0b ("dmaengine: mmp_pdma: add SpacemiT K3 support") incorrectly
set it to 0x1000, causing DRCMR accesses for request IDs >= 64 to target
offsets 0x100 too low.

The 0x1100 base has been verified on K3 silicon using real SPI and QSPI
DMA transactions. The K3 DMA documentation [1] was updated on June 24,
2026, to reflect the corrected register addresses.

Drop the bogus DRCMR_EXT_BASE_K3 macro and reuse
DRCMR_EXT_BASE_DEFAULT for the K3 ops.

Fixes: 6587b8661a0b ("dmaengine: mmp_pdma: add SpacemiT K3 support")
Link: https://www.spacemit.com/community/document/info?nodepath=hardware/key_stone/k3/k3_docs/k3_usermanual/16_peripherals/dma.md&lang=en [1]
Signed-off-by: Troy Mitchell <troy.mitchell at linux.spacemit.com>
---
This is a minimal fix for the wrong DRCMR_EXT_BASE_K3 value introduced
by commit 6587b8661a0b ("dmaengine: mmp_pdma: add SpacemiT K3 support").
K3 silicon uses 0x1100 as the extended DRCMR base, so the K3 ops now
reuse DRCMR_EXT_BASE_DEFAULT.

I deliberately kept the per-ops drcmr_ext_base field and the
DRCMR_EXT_BASE_DEFAULT macro to preserve the extensibility that was
introduced together with the helper refactor, in case a future PDMA
variant ends up using a different extended base. If reviewers prefer
to drop this abstraction entirely and collapse it back to a single
constant now that all known users share the same value, I am happy to
send a v3 that removes the drcmr_ext_base ops field as a cleanup.
---
Changes in v2:
- Reword the commit message to remove the inaccurate K1 comparison.
- Mention successful SPI and QSPI DMA tests on K3 silicon in the commit
  message.
- Add a link to the corrected K3 DMA documentation, updated June 24,
  2026.
- Link to v1: https://patch.msgid.link/20260615-k3-pdma-fix-drcmr-base-v1-1-ee1af124199f@linux.spacemit.com

To: Vinod Koul <vkoul at kernel.org>
To: Frank Li <Frank.Li at kernel.org>
To: Yixun Lan <dlan at kernel.org>
To: Guodong Xu <guodong at riscstar.com>
To: Troy Mitchell <troy.mitchell at linux.spacemit.com>
To: Paul Walmsley <pjw at kernel.org>
To: Palmer Dabbelt <palmer at dabbelt.com>
To: Albert Ou <aou at eecs.berkeley.edu>
To: Alexandre Ghiti <alex at ghiti.fr>
Cc: dmaengine at vger.kernel.org
Cc: linux-kernel at vger.kernel.org
Cc: linux-riscv at lists.infradead.org
Cc: spacemit at lists.linux.dev
---
 drivers/dma/mmp_pdma.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c
index 386e85cd4882..78e3e07e681d 100644
--- a/drivers/dma/mmp_pdma.c
+++ b/drivers/dma/mmp_pdma.c
@@ -52,7 +52,6 @@
 #define DCSR_EORINTR	BIT(9)	/* The end of Receive */
 
 #define DRCMR_BASE		0x0100
-#define DRCMR_EXT_BASE_K3	0x1000
 #define DRCMR_EXT_BASE_DEFAULT	0x1100
 #define DRCMR_REQ_LIMIT		64
 #define DRCMR_MAPVLD	BIT(7)	/* Map Valid (read / write) */
@@ -1219,7 +1218,7 @@ static const struct mmp_pdma_ops spacemit_k3_pdma_ops = {
 	.get_desc_dst_addr = get_desc_dst_addr_64,
 	.run_bits = (DCSR_RUN | DCSR_LPAEEN | DCSR_EORIRQEN | DCSR_EORSTOPEN),
 	.dma_width = 64,
-	.drcmr_ext_base = DRCMR_EXT_BASE_K3,
+	.drcmr_ext_base = DRCMR_EXT_BASE_DEFAULT,
 };
 
 static const struct of_device_id mmp_pdma_dt_ids[] = {

---
base-commit: c425609d6ac4012c8bbf01ec2e10e801b1923a7b
change-id: 20260615-k3-pdma-fix-drcmr-base-326536770427

Best regards,
--  
Troy Mitchell <troy.mitchell at linux.spacemit.com>