[PATCH v2] clk: qcom: clk-rpmh: Fix overflow in BCM vote

From: Imran Shaik
Date: Fri Aug 09 2024 - 01:22:23 EST


From: Mike Tipton <quic_mdtipton@xxxxxxxxxxx>

Valid frequencies may result in BCM votes that exceed the max HW value.
Set vote ceiling to BCM_TCS_CMD_VOTE_MASK to ensure the votes aren't
truncated, which can result in lower frequencies than desired.

Fixes: 04053f4d23a4 ("clk: qcom: clk-rpmh: Add IPA clock support")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mike Tipton <quic_mdtipton@xxxxxxxxxxx>
Reviewed-by: Taniya Das <quic_tdas@xxxxxxxxxxx>
Signed-off-by: Imran Shaik <quic_imrashai@xxxxxxxxxxx>
---
Changes in v2:
- Updated the overflow check as per the comment from Stephen.
- Link to v1: https://lore.kernel.org/r/20240808-clk-rpmh-bcm-vote-fix-v1-1-109bd1d76189@xxxxxxxxxxx
---
drivers/clk/qcom/clk-rpmh.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/clk/qcom/clk-rpmh.c b/drivers/clk/qcom/clk-rpmh.c
index bb82abeed88f..4acde937114a 100644
--- a/drivers/clk/qcom/clk-rpmh.c
+++ b/drivers/clk/qcom/clk-rpmh.c
@@ -263,6 +263,8 @@ static int clk_rpmh_bcm_send_cmd(struct clk_rpmh *c, bool enable)
cmd_state = 0;
}

+ cmd_state = min(cmd_state, BCM_TCS_CMD_VOTE_MASK);
+
if (c->last_sent_aggr_state != cmd_state) {
cmd.addr = c->res_addr;
cmd.data = BCM_TCS_CMD(1, enable, 0, cmd_state);

---
base-commit: 222a3380f92b8791d4eeedf7cd750513ff428adf
change-id: 20240808-clk-rpmh-bcm-vote-fix-c344e213c9bb

Best regards,
--
Imran Shaik <quic_imrashai@xxxxxxxxxxx>