]> git.baikalelectronics.ru Git - kernel.git/commitdiff
dmascc: use proper 'virt_to_bus()' rather than casting to 'int'
authorLinus Torvalds <torvalds@linux-foundation.org>
Sun, 19 Sep 2021 17:49:42 +0000 (10:49 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sun, 19 Sep 2021 17:49:42 +0000 (10:49 -0700)
The old dmascc driver depends on the legacy ISA_DMA_API, and blindly
just casts the kernel virtual address to 'int' for set_dma_addr().

That works only incidentally, and because the high bits of the address
will be ignored anyway. And on 64-bit architectures it causes warnings.

Admittedly, 64-bit architectures with ISA are basically dead - I think
the only example of this is alpha, and nobody would ever use the dmascc
driver there.  But hey, the fix is easy enough, the end result is
cleaner, and it's yet another configuration that now builds without
warnings.

If somebody actually uses this driver on an alpha and this fixes it for
you, please email me.  Because that is just incredibly bizarre.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/net/hamradio/dmascc.c

index b50b7fafd8d6c525d34a05de696acefa496605ac..f4c3efc3e0745c621d8e1ff6bea66b1c8efb5be6 100644 (file)
@@ -973,7 +973,7 @@ static inline void tx_on(struct scc_priv *priv)
                flags = claim_dma_lock();
                set_dma_mode(priv->param.dma, DMA_MODE_WRITE);
                set_dma_addr(priv->param.dma,
-                            (int) priv->tx_buf[priv->tx_tail] + n);
+                            virt_to_bus(priv->tx_buf[priv->tx_tail]) + n);
                set_dma_count(priv->param.dma,
                              priv->tx_len[priv->tx_tail] - n);
                release_dma_lock(flags);
@@ -1020,7 +1020,7 @@ static inline void rx_on(struct scc_priv *priv)
                flags = claim_dma_lock();
                set_dma_mode(priv->param.dma, DMA_MODE_READ);
                set_dma_addr(priv->param.dma,
-                            (int) priv->rx_buf[priv->rx_head]);
+                            virt_to_bus(priv->rx_buf[priv->rx_head]));
                set_dma_count(priv->param.dma, BUF_SIZE);
                release_dma_lock(flags);
                enable_dma(priv->param.dma);
@@ -1233,7 +1233,7 @@ static void special_condition(struct scc_priv *priv, int rc)
                if (priv->param.dma >= 0) {
                        flags = claim_dma_lock();
                        set_dma_addr(priv->param.dma,
-                                    (int) priv->rx_buf[priv->rx_head]);
+                                    virt_to_bus(priv->rx_buf[priv->rx_head]));
                        set_dma_count(priv->param.dma, BUF_SIZE);
                        release_dma_lock(flags);
                } else {