From 63cbabb003ba314be113700ca58ec320b6ce2b33 Mon Sep 17 00:00:00 2001 From: AngeloGioacchino Del Regno Date: Fri, 23 Jan 2026 10:20:31 -0800 Subject: [PATCH] spmi: mtk-pmif: Keep spinlock until read is fully done MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Move the spin unlocking to after reading the contents of the PMIF_SWINF_(x)_RDATA_31_0 register in pmif_spmi_read_cmd(): since this is the only register that we can read to get the data from all of the arbitered busses, a concurrent request for reading (especially on a busy arbiter) will show a race condition and a unexpected or corrupted value may be read. Doing the entire read sequence while spin locked guarantees that concurrent access to the arbiter doesn't happen. Fixes: f200fff8d019 ("spmi: mtk-pmif: Serialize PMIF status check and command submission") Reviewed-by: Nícolas F. R. A. Prado Reviewed-by: Chen-Yu Tsai Signed-off-by: AngeloGioacchino Del Regno Signed-off-by: Stephen Boyd Fixes: b45b3ccef8c0 ("spmi: mediatek: Add support for MT6873/8192") Link: https://patch.msgid.link/20260123182039.224314-4-sboyd@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/spmi/spmi-mtk-pmif.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/spmi/spmi-mtk-pmif.c b/drivers/spmi/spmi-mtk-pmif.c index 68f458587c67..9f416b231ab8 100644 --- a/drivers/spmi/spmi-mtk-pmif.c +++ b/drivers/spmi/spmi-mtk-pmif.c @@ -22,7 +22,7 @@ #define PMIF_CMD_EXT_REG 2 #define PMIF_CMD_EXT_REG_LONG 3 -#define PMIF_DELAY_US 10 +#define PMIF_DELAY_US 2 #define PMIF_TIMEOUT_US (10 * 1000) #define PMIF_CHAN_OFFSET 0x5 @@ -372,7 +372,6 @@ static int pmif_spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid, /* Send the command. */ cmd = (opc << 30) | (sid << 24) | ((len - 1) << 16) | addr; pmif_writel(arb, pbus, cmd, inf_reg->ch_send); - raw_spin_unlock_irqrestore(&pbus->lock, flags); /* * Wait for Software Interface FSM state to be WFVLDCLR, @@ -382,13 +381,16 @@ static int pmif_spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid, data, GET_SWINF(data) == SWINF_WFVLDCLR, PMIF_DELAY_US, PMIF_TIMEOUT_US); if (ret < 0) { + raw_spin_unlock_irqrestore(&pbus->lock, flags); dev_err(&ctrl->dev, "failed to wait for SWINF_WFVLDCLR\n"); return ret; } data = pmif_readl(arb, pbus, inf_reg->rdata); - memcpy(buf, &data, len); pmif_writel(arb, pbus, 1, inf_reg->ch_rdy); + raw_spin_unlock_irqrestore(&pbus->lock, flags); + + memcpy(buf, &data, len); return 0; } -- 2.47.3