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From 793023dc148830c18c437b58d88a118a72091038 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Thu, 13 Apr 2023 16:47:10 +0200
Subject: [PATCH] dmaengine: bcm2835: Fix descriptors usage for 40-bits
channels
The bcm2835_dma_create_cb_chain() function is in charge of building up
the descriptors chain for a given transfer.
It was initially supporting only the BCM2835-style DMA controller, and
was later expanded to support controllers with 40-bits channels that use
a different descriptor layout.
However, some part of the function only use the old style descriptor,
even when building a chain of new-style descriptors, resulting in weird
bugs.
Fixes: 9a52a9918306 ("bcm2835-dma: Add proper 40-bit DMA support")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
drivers/dma/bcm2835-dma.c | 69 ++++++++++++++++++++++++++++-----------
1 file changed, 50 insertions(+), 19 deletions(-)
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -543,7 +543,10 @@ static struct bcm2835_desc *bcm2835_dma_
cyclic ? finalextrainfo : 0);
/* calculate new remaining length */
- len -= control_block->length;
+ if (c->is_40bit_channel)
+ len -= ((struct bcm2711_dma40_scb *)control_block)->len;
+ else
+ len -= control_block->length;
}
/* link this the last controlblock */
@@ -555,10 +558,19 @@ static struct bcm2835_desc *bcm2835_dma_
d->cb_list[frame - 1].cb->next = cb_entry->paddr;
/* update src and dst and length */
- if (src && (info & BCM2835_DMA_S_INC))
- src += control_block->length;
- if (dst && (info & BCM2835_DMA_D_INC))
- dst += control_block->length;
+ if (src && (info & BCM2835_DMA_S_INC)) {
+ if (c->is_40bit_channel)
+ src += ((struct bcm2711_dma40_scb *)control_block)->len;
+ else
+ src += control_block->length;
+ }
+
+ if (dst && (info & BCM2835_DMA_D_INC)) {
+ if (c->is_40bit_channel)
+ dst += ((struct bcm2711_dma40_scb *)control_block)->len;
+ else
+ dst += control_block->length;
+ }
/* Length of total transfer */
if (c->is_40bit_channel)
@@ -779,20 +791,39 @@ static size_t bcm2835_dma_desc_size_pos(
unsigned int i;
size_t size;
- for (size = i = 0; i < d->frames; i++) {
- struct bcm2835_dma_cb *control_block = d->cb_list[i].cb;
- size_t this_size = control_block->length;
- dma_addr_t dma;
-
- if (d->dir == DMA_DEV_TO_MEM)
- dma = control_block->dst;
- else
- dma = control_block->src;
-
- if (size)
- size += this_size;
- else if (addr >= dma && addr < dma + this_size)
- size += dma + this_size - addr;
+ if (d->c->is_40bit_channel) {
+ for (size = i = 0; i < d->frames; i++) {
+ struct bcm2711_dma40_scb *control_block =
+ (struct bcm2711_dma40_scb *)d->cb_list[i].cb;
+ size_t this_size = control_block->len;
+ dma_addr_t dma;
+
+ if (d->dir == DMA_DEV_TO_MEM)
+ dma = control_block->dst;
+ else
+ dma = control_block->src;
+
+ if (size)
+ size += this_size;
+ else if (addr >= dma && addr < dma + this_size)
+ size += dma + this_size - addr;
+ }
+ } else {
+ for (size = i = 0; i < d->frames; i++) {
+ struct bcm2835_dma_cb *control_block = d->cb_list[i].cb;
+ size_t this_size = control_block->length;
+ dma_addr_t dma;
+
+ if (d->dir == DMA_DEV_TO_MEM)
+ dma = control_block->dst;
+ else
+ dma = control_block->src;
+
+ if (size)
+ size += this_size;
+ else if (addr >= dma && addr < dma + this_size)
+ size += dma + this_size - addr;
+ }
}
return size;
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