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

commit 1e93ed26acf03fe6c97c6d573a10178596aadd43 upstream.

The systemid property was checked for in the wrong place of the device
tree and compared to the wrong value.

Fixes: 6cec9b07fe6a ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c
index 867e179ac304a7a83f8a748f0765a4a027d8f79b..ff6685f1683e94e6b7218b5247d83fbf630e0c24 100644 (file)
--- a/drivers/net/can/grcan.c
+++ b/drivers/net/can/grcan.c
@@ -241,7 +241,7 @@ struct grcan_device_config {
                .rxsize         = GRCAN_DEFAULT_BUFFER_SIZE,    \
                }
 
-#define GRCAN_TXBUG_SAFE_GRLIB_VERSION 0x4100
+#define GRCAN_TXBUG_SAFE_GRLIB_VERSION 4100
 #define GRLIB_VERSION_MASK             0xffff
 
 /* GRCAN private data structure */
@@ -1656,6 +1656,7 @@ exit_free_candev:
 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;
@@ -1664,10 +1665,15 @@ 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) {