[PATCH v6 2/6] spmi: apple: Validate FIFO state
Sasha Finkelstein <[email protected]>
| Newsgroups | dev.linux.lists.asahi,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
From: Alba Mendez <[email protected]> Check for data before reading the body of a reply, and check for end of data afterwards. Signed-off-by: Alba Mendez <[email protected]> Reviewed-by: Janne Grunau <[email protected]> Signed-off-by: Sasha Finkelstein <[email protected]> --- drivers/spmi/spmi-apple-controller.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/spmi/spmi-apple-controller.c b/drivers/spmi/spmi-apple-controller.c index 376cf682c43e..15721cb41d5c 100644 --- a/drivers/spmi/spmi-apple-controller.c +++ b/drivers/spmi/spmi-apple-controller.c @@ -21,7 +21,9 @@ #define SPMI_STATUS_REG 0 #define SPMI_CMD_REG 0x4 #define SPMI_RSP_REG 0x8 +#define SPMI_ACT_REG 0xa4 +#define SPMI_ACT_FIFO_FLUSH BIT(0) #define SPMI_RX_FIFO_EMPTY BIT(24) #define REG_POLL_INTERVAL_US 10000 @@ -29,6 +31,7 @@ struct apple_spmi { void __iomem *regs; + bool prev_fail; }; #define poll_reg(spmi, reg, val, cond) \ @@ -49,6 +52,7 @@ static int apple_spmi_wait_rx_not_empty(struct spmi_controller *ctrl) ret = poll_reg(spmi, SPMI_STATUS_REG, status, !(status & SPMI_RX_FIFO_EMPTY)); if (ret) { + spmi->prev_fail = true; dev_err(&ctrl->dev, "failed to wait for RX FIFO not empty\n"); return ret; @@ -67,6 +71,11 @@ static int spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid, u8 i; int ret; + if (spmi->prev_fail) { + writel(SPMI_ACT_FIFO_FLUSH, spmi->regs + SPMI_ACT_REG); + spmi->prev_fail = false; + } + writel(spmi_cmd, spmi->regs + SPMI_CMD_REG); ret = apple_spmi_wait_rx_not_empty(ctrl); @@ -78,6 +87,12 @@ 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) { + spmi->prev_fail = true; + dev_err_ratelimited(&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 +101,11 @@ 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"); + spmi->prev_fail = true; + } + return 0; } @@ -97,6 +117,11 @@ static int spmi_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid, size_t i = 0, j; int ret; + if (spmi->prev_fail) { + writel(SPMI_ACT_FIFO_FLUSH, spmi->regs + SPMI_ACT_REG); + spmi->prev_fail = false; + } + writel(spmi_cmd, spmi->regs + SPMI_CMD_REG); while (i < len) { @@ -115,6 +140,11 @@ 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"); + spmi->prev_fail = true; + } + return 0; } -- 2.55.0