| From b89e82f02345e0168ad3dece51d879778a815674 Mon Sep 17 00:00:00 2001 |
| From: Tom Craig <craigt@google.com> |
| Date: Sun, 4 May 2025 21:34:52 -0700 |
| Subject: [PATCH 9/9] mipi-i3c-hci: disable DMA *experimental* |
| |
| For experimentation purposes, disable DMA on mipi-i3c-hci. This |
| forces the I3C controllers on AST27xx A1 silicon to use PIO mode. |
| |
| Signed-off-by: Tom Craig <craigt@google.com> |
| --- |
| drivers/i3c/master/mipi-i3c-hci/core.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c |
| index 19df976ea267..5079ee8e478b 100644 |
| --- a/drivers/i3c/master/mipi-i3c-hci/core.c |
| +++ b/drivers/i3c/master/mipi-i3c-hci/core.c |
| @@ -1336,7 +1336,8 @@ static int i3c_hci_init(struct i3c_hci *hci) |
| |
| regval = reg_read(RING_HEADERS_SECTION); |
| offset = FIELD_GET(RING_HEADERS_OFFSET, regval); |
| - hci->RHS_regs = offset ? hci->base_regs + offset : NULL; |
| + hci->RHS_regs = NULL; // Disable DMA, force to use PIO mode. |
| + // hci->RHS_regs = offset ? hci->base_regs + offset : NULL; |
| dev_info(&hci->master.dev, "Ring Headers at offset %#x\n", offset); |
| |
| regval = reg_read(PIO_SECTION); |
| -- |
| 2.49.0.906.g1f30a19c02-goog |
| |
