openwrt/target/linux/bcm27xx/patches-6.6/950-1381-dmaengine-dw-axi-dmac-Only-start-idle-channels.patch
Álvaro Fernández Rojas 3a5584e0df bcm27xx: pull 6.6 patches from RPi repo
Adds latest 6.6 patches from the Raspberry Pi repository.

These patches were generated from:
https://github.com/raspberrypi/linux/commits/rpi-6.6.y/
With the following command:
git format-patch -N v6.6.67..HEAD
(HEAD -> 811ff707533bcd67cdcd368bbd46223082009b12)

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
(cherry picked from commit 692205305db14deeff1a2dc4a6d7f87e19fc418b)
2024-12-28 14:11:52 +01:00

30 lines
1.1 KiB
Diff

From 59a8855b51c1d8acf37d3c80f34782d71f474617 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Wed, 13 Nov 2024 10:37:22 +0000
Subject: [PATCH] dmaengine: dw-axi-dmac: Only start idle channels
Attempting to start a non-idle channel causes an error message to be
logged, and is inefficient. Test for emptiness of the desc_issued list
before doing so.
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -536,9 +536,11 @@ static void dma_chan_issue_pending(struc
{
struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
unsigned long flags;
+ bool was_empty;
spin_lock_irqsave(&chan->vc.lock, flags);
- if (vchan_issue_pending(&chan->vc))
+ was_empty = list_empty(&chan->vc.desc_issued);
+ if (vchan_issue_pending(&chan->vc) && was_empty)
axi_chan_start_first_queued(chan);
spin_unlock_irqrestore(&chan->vc.lock, flags);
}