[PATCH 5.4 06/18] can: grcan: grcan_probe(): fix broken system id check for errata workaround needs

Greg Kroah-Hartman
2022-05-13T14:32:01Z

From: Andreas Larsson <andreas@gaisler.com>

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>
---
drivers/net/can/grcan.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

--- 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;
struct resource *res;
u32 sysid, ambafreq;
int irq, err;
@@ -1665,10 +1666,15 @@ static int grcan_probe(struct platform_d
/* 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) {