[PATCH v2 2/7] spmi: apple: Validate FIFO state
From: Sasha Finkelstein
Date: Tue Jul 28 2026 - 05:42:11 EST
From: Alba Mendez <me@xxxxxxx>
Check for data before reading the body of a reply, and check for
end of data afterwards.
Signed-off-by: Alba Mendez <me@xxxxxxx>
Signed-off-by: Sasha Finkelstein <k@xxxxxxxxxxxxxx>
---
drivers/spmi/spmi-apple-controller.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/spmi/spmi-apple-controller.c b/drivers/spmi/spmi-apple-controller.c
index 376cf682c43e..b4f442d0b4ad 100644
--- a/drivers/spmi/spmi-apple-controller.c
+++ b/drivers/spmi/spmi-apple-controller.c
@@ -78,6 +78,10 @@ static int spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
/* Read SPMI data reply */
while (len_read < len) {
+ if (readl(spmi->regs + SPMI_STATUS_REG) & SPMI_RX_FIFO_EMPTY) {
+ dev_err(&ctrl->dev, "FIFO lacks reply data, controller stuck?\n");
+ return -EIO;
+ }
rsp = readl(spmi->regs + SPMI_RSP_REG);
i = 0;
while ((len_read < len) && (i < 4)) {
@@ -86,6 +90,9 @@ static int spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
}
}
+ if (!(readl(spmi->regs + SPMI_STATUS_REG) & SPMI_RX_FIFO_EMPTY))
+ dev_warn(&ctrl->dev, "FIFO has extra data\n");
+
return 0;
}
@@ -115,6 +122,9 @@ static int spmi_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
/* Discard */
readl(spmi->regs + SPMI_RSP_REG);
+ if (!(readl(spmi->regs + SPMI_STATUS_REG) & SPMI_RX_FIFO_EMPTY))
+ dev_warn(&ctrl->dev, "FIFO has extra data\n");
+
return 0;
}
--
2.55.0