HSD#22021259142: i3c: dw-i3c: Treat TX/RX length mismatch as M0 error

Enhance error handling for Common Command Code (CCC) operations in the
DesignWare I3C master driver:

* Define GET_MRL_MIN_LEN (2) for validating GETMRL responses.
* In dw_i3c_ccc_get(), treat an RX length smaller than the expected
  payload length or smaller than GET_MRL_MIN_LEN for GETMRL as an
  M0 (frame) error and return -EIO.
* In dw_i3c_ccc_set(), similarly map RX length mismatches to I3C_ERROR_M0.

These changes improve robustness by flagging incomplete or malformed
responses during CCC transfers rather than silently accepting truncated
data.

Signed-off-by: Adrian Ng Ho Yin <adrianhoyin.ng@altera.com>

Author: hoyin0722

drivers/i3c/master/dw-i3c-master.c

@@ -226,6 +226,8 @@
 
 #define GET_IBI_SIR_BIT_INDEX(x) ((((x) & 0x1F) + (((x) >> 5) & 0x03)) % 32)
 
+#define GET_MRL_MIN_LEN 2
+
 struct dw_i3c_cmd {
 	u32 cmd_lo;
 	u32 cmd_hi;
@@ -774,7 +776,8 @@ static int dw_i3c_ccc_set(struct dw_i3c_master *master,
 			xfer->cmds[0].error == RESPONSE_ERROR_ADDRESS_NACK)
 		ccc->err = I3C_ERROR_M2;
 
-	if (xfer->cmds[0].error == RESPONSE_ERROR_FRAME)
+	if (xfer->cmds[0].error == RESPONSE_ERROR_FRAME ||
+			(cmd->rx_len < ccc->dests[0].payload.len))
 		ccc->err = I3C_ERROR_M0;
 
 	dw_i3c_master_free_xfer(xfer);
@@ -787,6 +790,7 @@ static int dw_i3c_ccc_get(struct dw_i3c_master *master, struct i3c_ccc_cmd *ccc)
 	struct dw_i3c_xfer *xfer;
 	struct dw_i3c_cmd *cmd;
 	int ret, pos;
+	bool rx_len_mismatch;
 
 	pos = dw_i3c_master_get_addr_pos(master, ccc->dests[0].addr);
 	if (pos < 0)
@@ -820,8 +824,15 @@ static int dw_i3c_ccc_get(struct dw_i3c_master *master, struct i3c_ccc_cmd *ccc)
 			xfer->cmds[0].error == RESPONSE_ERROR_ADDRESS_NACK)
 		ccc->err = I3C_ERROR_M2;
 
-	if (xfer->cmds[0].error == RESPONSE_ERROR_FRAME)
+	if (ccc->id == I3C_CCC_GETMRL)
+		rx_len_mismatch = (cmd->rx_len < GET_MRL_MIN_LEN);
+	else
+		rx_len_mismatch = (cmd->rx_len < ccc->dests[0].payload.len);
+
+	if (xfer->cmds[0].error == RESPONSE_ERROR_FRAME || rx_len_mismatch) {
 		ccc->err = I3C_ERROR_M0;
+		ret = -EIO;
+	}
 
 	dw_i3c_master_free_xfer(xfer);