This is a note to let you know that I've just added the patch titled
net: dsa: qca8k: fix regmap bulk read/write methods on big endian systems
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-dsa-qca8k-fix-regmap-bulk-read-write-methods-on-.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b00502870a37a16355c94d51269e1d12272b87aa
Author: Marek Behún <kabel@xxxxxxxxxx>
Date: Wed Oct 4 11:19:03 2023 +0200
net: dsa: qca8k: fix regmap bulk read/write methods on big endian systems
[ Upstream commit 5652d1741574eb89cc02576e50ee3e348bd6dd77 ]
Commit c766e077d927 ("net: dsa: qca8k: convert to regmap read/write
API") introduced bulk read/write methods to qca8k's regmap.
The regmap bulk read/write methods get the register address in a buffer
passed as a void pointer parameter (the same buffer contains also the
read/written values). The register address occupies only as many bytes
as it requires at the beginning of this buffer. For example if the
.reg_bits member in regmap_config is 16 (as is the case for this
driver), the register address occupies only the first 2 bytes in this
buffer, so it can be cast to u16.
But the original commit implementing these bulk read/write methods cast
the buffer to u32:
u32 reg = *(u32 *)reg_buf & U16_MAX;
taking the first 4 bytes. This works on little endian systems where the
first 2 bytes of the buffer correspond to the low 16-bits, but it
obviously cannot work on big endian systems.
Fix this by casting the beginning of the buffer to u16 as
u32 reg = *(u16 *)reg_buf;
Fixes: c766e077d927 ("net: dsa: qca8k: convert to regmap read/write API")
Signed-off-by: Marek Behún <kabel@xxxxxxxxxx>
Tested-by: Christian Marangi <ansuelsmth@xxxxxxxxx>
Reviewed-by: Christian Marangi <ansuelsmth@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c
index efe9380d4a15d..8e1574c63954e 100644
--- a/drivers/net/dsa/qca/qca8k-8xxx.c
+++ b/drivers/net/dsa/qca/qca8k-8xxx.c
@@ -505,8 +505,8 @@ qca8k_bulk_read(void *ctx, const void *reg_buf, size_t reg_len,
void *val_buf, size_t val_len)
{
int i, count = val_len / sizeof(u32), ret;
- u32 reg = *(u32 *)reg_buf & U16_MAX;
struct qca8k_priv *priv = ctx;
+ u32 reg = *(u16 *)reg_buf;
if (priv->mgmt_master &&
!qca8k_read_eth(priv, reg, val_buf, val_len))
@@ -527,8 +527,8 @@ qca8k_bulk_gather_write(void *ctx, const void *reg_buf, size_t reg_len,
const void *val_buf, size_t val_len)
{
int i, count = val_len / sizeof(u32), ret;
- u32 reg = *(u32 *)reg_buf & U16_MAX;
struct qca8k_priv *priv = ctx;
+ u32 reg = *(u16 *)reg_buf;
u32 *val = (u32 *)val_buf;
if (priv->mgmt_master &&
