git.openwrt.org Git - openwrt/staging/ldir.git/blob

   1 From 793023dc148830c18c437b58d88a118a72091038 Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Thu, 13 Apr 2023 16:47:10 +0200
   4 Subject: [PATCH] dmaengine: bcm2835: Fix descriptors usage for 40-bits
   5  channels
   6
   7 The bcm2835_dma_create_cb_chain() function is in charge of building up
   8 the descriptors chain for a given transfer.
   9
  10 It was initially supporting only the BCM2835-style DMA controller, and
  11 was later expanded to support controllers with 40-bits channels that use
  12 a different descriptor layout.
  13
  14 However, some part of the function only use the old style descriptor,
  15 even when building a chain of new-style descriptors, resulting in weird
  16 bugs.
  17
  18 Fixes: 9a52a9918306 ("bcm2835-dma: Add proper 40-bit DMA support")
  19 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  20 ---
  21  drivers/dma/bcm2835-dma.c | 69 ++++++++++++++++++++++++++++-----------
  22  1 file changed, 50 insertions(+), 19 deletions(-)
  23
  24 --- a/drivers/dma/bcm2835-dma.c
  25 +++ b/drivers/dma/bcm2835-dma.c
  26 @@ -543,7 +543,10 @@ static struct bcm2835_desc *bcm2835_dma_
  27                                 cyclic ? finalextrainfo : 0);
  28
  29                         /* calculate new remaining length */
  30 -                       len -= control_block->length;
  31 +                       if (c->is_40bit_channel)
  32 +                               len -= ((struct bcm2711_dma40_scb *)control_block)->len;
  33 +                       else
  34 +                               len -= control_block->length;
  35                 }
  36
  37                 /* link this the last controlblock */
  38 @@ -555,10 +558,19 @@ static struct bcm2835_desc *bcm2835_dma_
  39                         d->cb_list[frame - 1].cb->next = cb_entry->paddr;
  40
  41                 /* update src and dst and length */
  42 -               if (src && (info & BCM2835_DMA_S_INC))
  43 -                       src += control_block->length;
  44 -               if (dst && (info & BCM2835_DMA_D_INC))
  45 -                       dst += control_block->length;
  46 +               if (src && (info & BCM2835_DMA_S_INC)) {
  47 +                       if (c->is_40bit_channel)
  48 +                               src += ((struct bcm2711_dma40_scb *)control_block)->len;
  49 +                       else
  50 +                               src += control_block->length;
  51 +               }
  52 +
  53 +               if (dst && (info & BCM2835_DMA_D_INC)) {
  54 +                       if (c->is_40bit_channel)
  55 +                               dst += ((struct bcm2711_dma40_scb *)control_block)->len;
  56 +                       else
  57 +                               dst += control_block->length;
  58 +               }
  59
  60                 /* Length of total transfer */
  61                 if (c->is_40bit_channel)
  62 @@ -779,20 +791,39 @@ static size_t bcm2835_dma_desc_size_pos(
  63         unsigned int i;
  64         size_t size;
  65
  66 -       for (size = i = 0; i < d->frames; i++) {
  67 -               struct bcm2835_dma_cb *control_block = d->cb_list[i].cb;
  68 -               size_t this_size = control_block->length;
  69 -               dma_addr_t dma;
  70 -
  71 -               if (d->dir == DMA_DEV_TO_MEM)
  72 -                       dma = control_block->dst;
  73 -               else
  74 -                       dma = control_block->src;
  75 -
  76 -               if (size)
  77 -                       size += this_size;
  78 -               else if (addr >= dma && addr < dma + this_size)
  79 -                       size += dma + this_size - addr;
  80 +       if (d->c->is_40bit_channel) {
  81 +               for (size = i = 0; i < d->frames; i++) {
  82 +                       struct bcm2711_dma40_scb *control_block =
  83 +                               (struct bcm2711_dma40_scb *)d->cb_list[i].cb;
  84 +                       size_t this_size = control_block->len;
  85 +                       dma_addr_t dma;
  86 +
  87 +                       if (d->dir == DMA_DEV_TO_MEM)
  88 +                               dma = control_block->dst;
  89 +                       else
  90 +                               dma = control_block->src;
  91 +
  92 +                       if (size)
  93 +                               size += this_size;
  94 +                       else if (addr >= dma && addr < dma + this_size)
  95 +                               size += dma + this_size - addr;
  96 +               }
  97 +       } else {
  98 +               for (size = i = 0; i < d->frames; i++) {
  99 +                       struct bcm2835_dma_cb *control_block = d->cb_list[i].cb;
 100 +                       size_t this_size = control_block->length;
 101 +                       dma_addr_t dma;
 102 +
 103 +                       if (d->dir == DMA_DEV_TO_MEM)
 104 +                               dma = control_block->dst;
 105 +                       else
 106 +                               dma = control_block->src;
 107 +
 108 +                       if (size)
 109 +                               size += this_size;
 110 +                       else if (addr >= dma && addr < dma + this_size)
 111 +                               size += dma + this_size - addr;
 112 +               }
 113         }
 114
 115         return size;