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| author | Adrian Hunter <adrian.hunter@intel.com> | 2026-01-13 10:26:42 +0300 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2026-01-14 19:21:09 +0300 |
| commit | 78f63ae4a82db173f93adca462e63d11ba06b126 (patch) | |
| tree | 907ebee3ae7e37f19c5933b53ed60ef9d8742238 | |
| parent | 3502cea99c7ceb331458cbd34ef6792c83144687 (diff) | |
| download | linux-78f63ae4a82db173f93adca462e63d11ba06b126.tar.xz | |
i3c: mipi-i3c-hci: Reset RING_OPERATION1 fields during init
The MIPI I3C HCI specification does not define reset values for
RING_OPERATION1 fields, and some controllers (e.g., Intel) do not clear
them during a software reset. Ensure the ring pointers are explicitly
set to zero during bus initialization to avoid inconsistent state.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260113072702.16268-2-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
| -rw-r--r-- | drivers/i3c/master/mipi-i3c-hci/dma.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index 0f6bbe184e85..5515ed740ca4 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -340,6 +340,14 @@ static int hci_dma_init(struct i3c_hci *hci) rh_reg_write(INTR_SIGNAL_ENABLE, regval); ring_ready: + /* + * The MIPI I3C HCI specification does not document reset values for + * RING_OPERATION1 fields and some controllers (e.g. Intel controllers) + * do not reset the values, so ensure the ring pointers are set to zero + * here. + */ + rh_reg_write(RING_OPERATION1, 0); + rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE | RING_CTRL_RUN_STOP); } |