linux-kernel - [PATCH v2 5/8] dmaengine: ep93xx: Prepare clock before using it

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 26 Jul 2021 16:59:53 +0300
From:   Nikita Shubin <nikita.shubin@...uefel.me>
To:     Alexander Sverdlin <alexander.sverdlin@...il.com>,
        Geert Uytterhoeven <geert@...ux-m68k.org>
Cc:     Nikita Shubin <nikita.shubin@...uefel.me>,
        Vinod Koul <vkoul@...nel.org>,
        dmaengine@...r.kernel.org (open list:DMA GENERIC OFFLOAD ENGINE
        SUBSYSTEM), linux-kernel@...r.kernel.org (open list)
Subject: [PATCH v2 5/8] dmaengine: ep93xx: Prepare clock before using it

From: Alexander Sverdlin <alexander.sverdlin@...il.com>

Use clk_prepare_enable()/clk_disable_unprepare() in preparation for switch
to Common Clock Framework, otherwise the following is visible:

WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:1011 clk_core_enable+0x9c/0xbc
Enabling unprepared m2p0
...
Hardware name: Cirrus Logic EDB9302 Evaluation Board
...
clk_core_enable
clk_core_enable_lock
ep93xx_dma_alloc_chan_resources
dma_chan_get
find_candidate
__dma_request_channel
snd_dmaengine_pcm_request_channel
dmaengine_pcm_new
snd_soc_pcm_component_new
soc_new_pcm
snd_soc_bind_card
edb93xx_probe
...
ep93xx-i2s ep93xx-i2s: Missing dma channel for stream: 0
ep93xx-i2s ep93xx-i2s: ASoC: error at snd_soc_pcm_component_new on ep93xx-i2s: -22
edb93xx-audio edb93xx-audio: ASoC: can't create pcm CS4271 HiFi :-22
edb93xx-audio edb93xx-audio: snd_soc_register_card() failed: -22
edb93xx-audio: probe of edb93xx-audio failed with error -22

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@...il.com>
Signed-off-by: Nikita Shubin <nikita.shubin@...uefel.me>
---
 drivers/dma/ep93xx_dma.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/ep93xx_dma.c b/drivers/dma/ep93xx_dma.c
index 01027779beb8..98f9ee70362e 100644
--- a/drivers/dma/ep93xx_dma.c
+++ b/drivers/dma/ep93xx_dma.c
@@ -897,7 +897,7 @@ static int ep93xx_dma_alloc_chan_resources(struct dma_chan *chan)
 	if (data && data->name)
 		name = data->name;

-	ret = clk_enable(edmac->clk);
+	ret = clk_prepare_enable(edmac->clk);
 	if (ret)
 		return ret;

@@ -936,7 +936,7 @@ static int ep93xx_dma_alloc_chan_resources(struct dma_chan *chan)
 fail_free_irq:
 	free_irq(edmac->irq, edmac);
 fail_clk_disable:
-	clk_disable(edmac->clk);
+	clk_disable_unprepare(edmac->clk);

 	return ret;
 }
@@ -969,7 +969,7 @@ static void ep93xx_dma_free_chan_resources(struct dma_chan *chan)
 	list_for_each_entry_safe(desc, d, &list, node)
 		kfree(desc);

-	clk_disable(edmac->clk);
+	clk_disable_unprepare(edmac->clk);
 	free_irq(edmac->irq, edmac);
 }

-- 
2.26.2