can: grcan: grcan_probe(): fix broken system id check for errata workaround needs

The systemid property was checked for in the wrong place of the device tree and compared to the wrong value. Fixes: 6cec9b0 ("can: grcan: Add device driver for GRCAN and GRHCAN cores") Link: https://lore.kernel.org/all/20220429084656.29788-3-andreas@gaisler.com Cc: stable@vger.kernel.org Signed-off-by: Andreas Larsson <andreas@gaisler.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Author: andreas-gaisler

drivers/net/can/grcan.c

@@ -241,7 +241,7 @@ struct grcan_device_config {
 .rxsize	= GRCAN_DEFAULT_BUFFER_SIZE,	\
 }
 
-#define GRCAN_TXBUG_SAFE_GRLIB_VERSION0x4100
+#define GRCAN_TXBUG_SAFE_GRLIB_VERSION4100
 #define GRLIB_VERSION_MASK0xffff
 
 /* GRCAN private data structure */
@@ -1643,6 +1643,7 @@ static int grcan_setup_netdev(struct platform_device *ofdev,
 static int grcan_probe(struct platform_device *ofdev)
 {
 struct device_node *np = ofdev->dev.of_node;
+struct device_node *sysid_parent;
 u32 sysid, ambafreq;
 int irq, err;
 void __iomem *base;
@@ -1651,10 +1652,15 @@ static int grcan_probe(struct platform_device *ofdev)
 /* Compare GRLIB version number with the first that does not
  * have the tx bug (see start_xmit)
  */
-err = of_property_read_u32(np, "systemid", &sysid);
-if (!err && ((sysid & GRLIB_VERSION_MASK)
- >= GRCAN_TXBUG_SAFE_GRLIB_VERSION))
-txbug = false;
+sysid_parent = of_find_node_by_path("/ambapp0");
+if (sysid_parent) {
+of_node_get(sysid_parent);
+err = of_property_read_u32(sysid_parent, "systemid", &sysid);
+if (!err && ((sysid & GRLIB_VERSION_MASK) >=
+ GRCAN_TXBUG_SAFE_GRLIB_VERSION))
+txbug = false;
+of_node_put(sysid_parent);
+}
 
 err = of_property_read_u32(np, "freq", &ambafreq);
 if (err) {