mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-16 14:51:51 -04:00
Code Issues Packages Projects Releases Wiki Activity

spmi: mtk-pmif: Keep spinlock until read is fully done

Browse Source 
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: f200fff8d0 ("spmi: mtk-pmif: Serialize PMIF status check and command submission")
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Fixes: b45b3ccef8 ("spmi: mediatek: Add support for MT6873/8192")
Link: https://patch.msgid.link/20260123182039.224314-4-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
AngeloGioacchino Del Regno
2026-01-23 10:20:31 -08:00
committed by Greg Kroah-Hartman
parent 078117963b
commit 63cbabb003
1 changed files with 5 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/spmi/spmi-mtk-pmif.c
View File

@@ -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;
}