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| author | Adrian Hunter <adrian.hunter@intel.com> | 2026-01-13 09:26:42 +0200 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2026-03-04 07:19:33 -0500 |
| commit | 0d9cdb7030653d71b3481decdb947b66b04a6386 (patch) | |
| tree | 3dc3e3ff14aabf5d9ffe8fed8e4562f5dbeba9f2 /drivers/i3c | |
| parent | 33f51b058c139f7e34869bcc6f4aafa975907cfd (diff) | |
| download | linux-0d9cdb7030653d71b3481decdb947b66b04a6386.tar.gz linux-0d9cdb7030653d71b3481decdb947b66b04a6386.tar.bz2 linux-0d9cdb7030653d71b3481decdb947b66b04a6386.zip | |
i3c: mipi-i3c-hci: Reset RING_OPERATION1 fields during init
[ Upstream commit 78f63ae4a82db173f93adca462e63d11ba06b126 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/i3c')
| -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 c401a9425cdc..951abfea5a6f 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -342,6 +342,14 @@ 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); } |