target/linux/d1/patches-6.1/0014-mmc-sunxi-mmc-Correct-the-maximum-segment-size.patch

   1 From 0e871e791a2530562851109346affa1c0d9987e0 Mon Sep 17 00:00:00 2001
   2 From: Samuel Holland <samuel@sholland.org>
   3 Date: Sun, 13 Jun 2021 23:15:56 -0500
   4 Subject: [PATCH 014/117] mmc: sunxi-mmc: Correct the maximum segment size
   5
   6 According to the DMA descriptor documentation, the lowest two bits of
   7 the size field are ignored, so the size must be rounded up to a multiple
   8 of 4 bytes. Furthermore, 0 is not a valid buffer size; setting the size
   9 to 0 will cause that DMA descriptor to be ignored.
  10
  11 Together, these restrictions limit the maximum DMA segment size to 4
  12 less than the power-of-two width of the size field.
  13
  14 Series-to: Ulf Hansson <ulf.hansson@linaro.org>
  15 Series-to: linux-mmc@vger.kernel.org
  16
  17 Fixes: 3cbcb16095f9 ("mmc: sunxi: Add driver for SD/MMC hosts found on Allwinner sunxi SoCs")
  18 Signed-off-by: Samuel Holland <samuel@sholland.org>
  19 ---
  20  drivers/mmc/host/sunxi-mmc.c | 14 ++++++++------
  21  1 file changed, 8 insertions(+), 6 deletions(-)
  22
  23 --- a/drivers/mmc/host/sunxi-mmc.c
  24 +++ b/drivers/mmc/host/sunxi-mmc.c
  25 @@ -214,6 +214,9 @@
  26  #define SDXC_IDMAC_DES0_CES    BIT(30) /* card error summary */
  27  #define SDXC_IDMAC_DES0_OWN    BIT(31) /* 1-idma owns it, 0-host owns it */
  28
  29 +/* Buffer size must be a multiple of 4 bytes. */
  30 +#define SDXC_IDMAC_SIZE_ALIGN  4
  31 +
  32  #define SDXC_CLK_400K          0
  33  #define SDXC_CLK_25M           1
  34  #define SDXC_CLK_50M           2
  35 @@ -361,17 +364,15 @@ static void sunxi_mmc_init_idma_des(stru
  36  {
  37         struct sunxi_idma_des *pdes = (struct sunxi_idma_des *)host->sg_cpu;
  38         dma_addr_t next_desc = host->sg_dma;
  39 -       int i, max_len = (1 << host->cfg->idma_des_size_bits);
  40 +       int i;
  41
  42         for (i = 0; i < data->sg_len; i++) {
  43                 pdes[i].config = cpu_to_le32(SDXC_IDMAC_DES0_CH |
  44                                              SDXC_IDMAC_DES0_OWN |
  45                                              SDXC_IDMAC_DES0_DIC);
  46
  47 -               if (data->sg[i].length == max_len)
  48 -                       pdes[i].buf_size = 0; /* 0 == max_len */
  49 -               else
  50 -                       pdes[i].buf_size = cpu_to_le32(data->sg[i].length);
  51 +               pdes[i].buf_size = cpu_to_le32(ALIGN(data->sg[i].length,
  52 +                                                    SDXC_IDMAC_SIZE_ALIGN));
  53
  54                 next_desc += sizeof(struct sunxi_idma_des);
  55                 pdes[i].buf_addr_ptr1 =
  56 @@ -1421,7 +1422,8 @@ static int sunxi_mmc_probe(struct platfo
  57         mmc->max_blk_count      = 8192;
  58         mmc->max_blk_size       = 4096;
  59         mmc->max_segs           = PAGE_SIZE / sizeof(struct sunxi_idma_des);
  60 -       mmc->max_seg_size       = (1 << host->cfg->idma_des_size_bits);
  61 +       mmc->max_seg_size       = (1 << host->cfg->idma_des_size_bits) -
  62 +                                 SDXC_IDMAC_SIZE_ALIGN;
  63         mmc->max_req_size       = mmc->max_seg_size * mmc->max_segs;
  64         /* 400kHz ~ 52MHz */
  65         mmc->f_min              =   400000;