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

   1 From 95d4bdad3bf5340b0bf1e53e28fcd487d9253315 Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Mon, 27 Mar 2023 17:10:07 +0200
   4 Subject: [PATCH] dmaengine: bcm2835: Fix position reporting for 40
   5  bits channels
   6
   7 For 40 bits channels, the position is reported by reading the upper byte
   8 in the SRCI/DESTI registers. However the driver adds that upper byte
   9 with an 8-bits left shift, while it should be 32.
  10
  11 Fixes: 9a52a9918306 ("bcm2835-dma: Add proper 40-bit DMA support")
  12 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  13 ---
  14  drivers/dma/bcm2835-dma.c | 27 ++++++++++++++++-----------
  15  1 file changed, 16 insertions(+), 11 deletions(-)
  16
  17 --- a/drivers/dma/bcm2835-dma.c
  18 +++ b/drivers/dma/bcm2835-dma.c
  19 @@ -819,20 +819,25 @@ static enum dma_status bcm2835_dma_tx_st
  20                 struct bcm2835_desc *d = c->desc;
  21                 dma_addr_t pos;
  22
  23 -               if (d->dir == DMA_MEM_TO_DEV && c->is_40bit_channel)
  24 -                       pos = readl(c->chan_base + BCM2711_DMA40_SRC) +
  25 -                               ((readl(c->chan_base + BCM2711_DMA40_SRCI) &
  26 -                                 0xff) << 8);
  27 -               else if (d->dir == DMA_MEM_TO_DEV && !c->is_40bit_channel)
  28 +               if (d->dir == DMA_MEM_TO_DEV && c->is_40bit_channel) {
  29 +                       u64 lo_bits, hi_bits;
  30 +
  31 +                       lo_bits = readl(c->chan_base + BCM2711_DMA40_SRC);
  32 +                       hi_bits = readl(c->chan_base + BCM2711_DMA40_SRCI) & 0xff;
  33 +                       pos = (hi_bits << 32) | lo_bits;
  34 +               } else if (d->dir == DMA_MEM_TO_DEV && !c->is_40bit_channel) {
  35                         pos = readl(c->chan_base + BCM2835_DMA_SOURCE_AD);
  36 -               else if (d->dir == DMA_DEV_TO_MEM && c->is_40bit_channel)
  37 -                       pos = readl(c->chan_base + BCM2711_DMA40_DEST) +
  38 -                               ((readl(c->chan_base + BCM2711_DMA40_DESTI) &
  39 -                                 0xff) << 8);
  40 -               else if (d->dir == DMA_DEV_TO_MEM && !c->is_40bit_channel)
  41 +               } else if (d->dir == DMA_DEV_TO_MEM && c->is_40bit_channel) {
  42 +                       u64 lo_bits, hi_bits;
  43 +
  44 +                       lo_bits = readl(c->chan_base + BCM2711_DMA40_DEST);
  45 +                       hi_bits = readl(c->chan_base + BCM2711_DMA40_DESTI) & 0xff;
  46 +                       pos = (hi_bits << 32) | lo_bits;
  47 +               } else if (d->dir == DMA_DEV_TO_MEM && !c->is_40bit_channel) {
  48                         pos = readl(c->chan_base + BCM2835_DMA_DEST_AD);
  49 -               else
  50 +               } else {
  51                         pos = 0;
  52 +               }
  53
  54                 txstate->residue = bcm2835_dma_desc_size_pos(d, pos);
  55         } else {