| Message ID | 20231004091904.16586-2-kabel@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 5652d1741574eb89cc02576e50ee3e348bd6dd77 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: dsa: qca8k: fix qca8k driver for Turris 1.x | expand |
On Wed, Oct 04, 2023 at 11:19:03AM +0200, Marek Behún wrote: > 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@kernel.org> Just find time to test this on a friend's big-endian device and can confirm this fix the problem. Thanks! Tested-by: Christian Marangi <ansuelsmth@gmail.com> Reviewed-by: Christian Marangi <ansuelsmth@gmail.com>
diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c index de1dc22cf683..d2df30640269 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 &&
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@kernel.org> --- drivers/net/dsa/qca/qca8k-8xxx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)