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author | Tomonori Sakita <tomonori.sakita@sord.co.jp> | 2019-01-25 05:02:22 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-23 10:18:56 +0300 |
commit | ddd02ed6687c8a09882c5f309ef32b366f01b5ed (patch) | |
tree | c161ec781738c350823bff2d0424c9281ef94487 | |
parent | 47bf7dbba48fff2fa66432704ea1d07917e96689 (diff) | |
download | linux-ddd02ed6687c8a09882c5f309ef32b366f01b5ed.tar.xz |
net: altera_tse: fix msgdma_tx_completion on non-zero fill_level case
[ Upstream commit 6571ebce112a21ec9be68ef2f53b96fcd41fd81b ]
If fill_level was not zero and status was not BUSY,
result of "tx_prod - tx_cons - inuse" might be zero.
Subtracting 1 unconditionally results invalid negative return value
on this case.
Make sure not to return an negative value.
Signed-off-by: Tomonori Sakita <tomonori.sakita@sord.co.jp>
Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Reviewed-by: Dalon L Westergreen <dalon.westergreen@linux.intel.com>
Acked-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r-- | drivers/net/ethernet/altera/altera_msgdma.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/ethernet/altera/altera_msgdma.c b/drivers/net/ethernet/altera/altera_msgdma.c index 0fb986ba3290..0ae723f75341 100644 --- a/drivers/net/ethernet/altera/altera_msgdma.c +++ b/drivers/net/ethernet/altera/altera_msgdma.c @@ -145,7 +145,8 @@ u32 msgdma_tx_completions(struct altera_tse_private *priv) & 0xffff; if (inuse) { /* Tx FIFO is not empty */ - ready = priv->tx_prod - priv->tx_cons - inuse - 1; + ready = max_t(int, + priv->tx_prod - priv->tx_cons - inuse - 1, 0); } else { /* Check for buffered last packet */ status = csrrd32(priv->tx_dma_csr, msgdma_csroffs(status)); |