Thread (3 messages) 3 messages, 3 authors, 2015-03-05
DORMANTno replies

[PATCH] mmc: sunxi: avoid invalid pointer calculation

From: Ulf Hansson <hidden>
Date: 2015-03-05 13:51:02
Also in: linux-mmc

On 24 February 2015 at 10:47, Arnd Bergmann [off-list ref] wrote:
The sunxi mmc driver tries to calculate a dma address by using pointer
arithmetic, which causes a warning when dma_addr_t is wider than a pointer:

drivers/mmc/host/sunxi-mmc.c: In function 'sunxi_mmc_init_idma_des':
drivers/mmc/host/sunxi-mmc.c:296:35: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  struct sunxi_idma_des *pdes_pa = (struct sunxi_idma_des *)host->sg_dma;
                                   ^

To avoid this warning and to simplify the logic, this changes
the code to avoid the cast and calculate the correct address
manually. The behavior should be unchanged.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Applied, thanks!

Kind regards
Uffe

quoted hunk ↗ jump to hunk
diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
index e8a4218b5726..c326ac965806 100644
--- a/drivers/mmc/host/sunxi-mmc.c
+++ b/drivers/mmc/host/sunxi-mmc.c
@@ -293,7 +293,7 @@ static void sunxi_mmc_init_idma_des(struct sunxi_mmc_host *host,
                                    struct mmc_data *data)
 {
        struct sunxi_idma_des *pdes = (struct sunxi_idma_des *)host->sg_cpu;
-       struct sunxi_idma_des *pdes_pa = (struct sunxi_idma_des *)host->sg_dma;
+       dma_addr_t next_desc = host->sg_dma;
        int i, max_len = (1 << host->idma_des_size_bits);

        for (i = 0; i < data->sg_len; i++) {
@@ -305,8 +305,9 @@ static void sunxi_mmc_init_idma_des(struct sunxi_mmc_host *host,
                else
                        pdes[i].buf_size = data->sg[i].length;

+               next_desc += sizeof(struct sunxi_idma_des);
                pdes[i].buf_addr_ptr1 = sg_dma_address(&data->sg[i]);
-               pdes[i].buf_addr_ptr2 = (u32)&pdes_pa[i + 1];
+               pdes[i].buf_addr_ptr2 = (u32)next_desc;
        }

        pdes[0].config |= SDXC_IDMAC_DES0_FD;
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