2022-05-13 11:50:58

by Andreas Larsson

[permalink] [raw]
Subject: [PATCH 4.9 1/2] can: grcan: grcan_probe(): fix broken system id check for errata workaround needs

backport of 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/[email protected]
Cc: [email protected]
Signed-off-by: Andreas Larsson <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>
---
drivers/net/can/grcan.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c
index a2dbd7ae9db2..e126516ba648 100644
--- a/drivers/net/can/grcan.c
+++ b/drivers/net/can/grcan.c
@@ -245,7 +245,7 @@ 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 */
@@ -1665,6 +1665,7 @@ 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;
struct resource *res;
u32 sysid, ambafreq;
int irq, err;
@@ -1674,10 +1675,15 @@ 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) {
--
2.17.1