[4.19.y-cip,48/57] ASoC: rsnd: src: Avoid a potential deadlock

Commit Message

Biju Das Oct. 17, 2019, 7:05 a.m. UTC

From: Jiada Wang <[e-mail]>

commit ba164a49f8f7390b036713bf8a70a150a938c670 upstream.

lockdep warns us that priv->lock and k->k_lock can cause a
deadlock when after acquire of k->k_lock, process is interrupted
by src, while in another routine of src .init, k->k_lock is
acquired with priv->lock held.

This patch avoids a potential deadlock by not calling soc_device_match()
in SRC .init callback, instead it adds new soc fields in priv->flags to
differentiate SoCs.

Fixes: linux-next commit 7674bec4fc09 ("ASoC: rsnd: update BSDSR/BSDISR handling")
Signed-off-by: Jiada Wang <[e-mail]>
Acked-by: Kuninori Morimoto <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>
Signed-off-by: Biju Das <[e-mail]>
---
 sound/soc/sh/rcar/core.c | 2 ++
 sound/soc/sh/rcar/rsnd.h | 5 +++++
 sound/soc/sh/rcar/src.c  | 9 +--------
 3 files changed, 8 insertions(+), 8 deletions(-)

Comments

Pavel Machek Oct. 27, 2019, 7:45 a.m. UTC | #1

On Thu 2019-10-17 08:05:20, Biju Das wrote:
> From: Jiada Wang <[e-mail]>
> 
> commit ba164a49f8f7390b036713bf8a70a150a938c670 upstream.
> 
> lockdep warns us that priv->lock and k->k_lock can cause a
> deadlock when after acquire of k->k_lock, process is interrupted
> by src, while in another routine of src .init, k->k_lock is
> acquired with priv->lock held.
> 
> This patch avoids a potential deadlock by not calling soc_device_match()
> in SRC .init callback, instead it adds new soc fields in priv->flags to
> differentiate SoCs.

Could this be moved near the patch it fixes? Or even merged to it?
Introducing deadlocks is bad for bisection at the very least...

Best regards,
								Pavel

Patch

diff --git a/sound/soc/sh/rcar/core.c b/sound/soc/sh/rcar/core.c
index 96d2b39..f361118 100644
--- a/sound/soc/sh/rcar/core.c
+++ b/sound/soc/sh/rcar/core.c
@@ -110,6 +110,8 @@  static const struct of_device_id rsnd_of_match[] = {
 	{ .compatible = "renesas,rcar_sound-gen1", .data = (void *)RSND_GEN1 },
 	{ .compatible = "renesas,rcar_sound-gen2", .data = (void *)RSND_GEN2 },
 	{ .compatible = "renesas,rcar_sound-gen3", .data = (void *)RSND_GEN3 },
+	/* Special Handling */
+	{ .compatible = "renesas,rcar_sound-r8a77990", .data = (void *)(RSND_GEN3 | RSND_SOC_E) },
 	{},
 };
 MODULE_DEVICE_TABLE(of, rsnd_of_match);
diff --git a/sound/soc/sh/rcar/rsnd.h b/sound/soc/sh/rcar/rsnd.h
index 90625c5..0e6ef4e1 100644
--- a/sound/soc/sh/rcar/rsnd.h
+++ b/sound/soc/sh/rcar/rsnd.h
@@ -607,6 +607,8 @@  struct rsnd_priv {
 #define RSND_GEN1	(1 << 0)
 #define RSND_GEN2	(2 << 0)
 #define RSND_GEN3	(3 << 0)
+#define RSND_SOC_MASK	(0xFF << 4)
+#define RSND_SOC_E	(1 << 4) /* E1/E2/E3 */
 
 	/*
 	 * below value will be filled on rsnd_gen_probe()
@@ -679,6 +681,9 @@  struct rsnd_priv {
 #define rsnd_is_gen1(priv)	(((priv)->flags & RSND_GEN_MASK) == RSND_GEN1)
 #define rsnd_is_gen2(priv)	(((priv)->flags & RSND_GEN_MASK) == RSND_GEN2)
 #define rsnd_is_gen3(priv)	(((priv)->flags & RSND_GEN_MASK) == RSND_GEN3)
+#define rsnd_is_e3(priv)	(((priv)->flags & \
+					(RSND_GEN_MASK | RSND_SOC_MASK)) == \
+					(RSND_GEN3 | RSND_SOC_E))
 
 #define rsnd_flags_has(p, f) ((p)->flags & (f))
 #define rsnd_flags_set(p, f) ((p)->flags |= (f))
diff --git a/sound/soc/sh/rcar/src.c b/sound/soc/sh/rcar/src.c
index db81e06..45096a6 100644
--- a/sound/soc/sh/rcar/src.c
+++ b/sound/soc/sh/rcar/src.c
@@ -14,7 +14,6 @@ 
  */
 
 #include "rsnd.h"
-#include <linux/sys_soc.h>
 
 #define SRC_NAME "src"
 
@@ -189,18 +188,12 @@  const static u32 chan222222[] = {
 	0x00000006, /* 1 to 2 */
 };
 
-static const struct soc_device_attribute ov_soc[] = {
-	{ .soc_id = "r8a77990" }, /* E3 */
-	{ /* sentinel */ }
-};
-
 static void rsnd_src_set_convert_rate(struct rsnd_dai_stream *io,
 				      struct rsnd_mod *mod)
 {
 	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
 	struct device *dev = rsnd_priv_to_dev(priv);
 	struct snd_pcm_runtime *runtime = rsnd_io_to_runtime(io);
-	const struct soc_device_attribute *soc = soc_device_match(ov_soc);
 	int is_play = rsnd_io_is_play(io);
 	int use_src = 0;
 	u32 fin, fout;
@@ -307,7 +300,7 @@  static void rsnd_src_set_convert_rate(struct rsnd_dai_stream *io,
 	/*
 	 * E3 need to overwrite
 	 */
-	if (soc)
+	if (rsnd_is_e3(priv))
 		switch (rsnd_mod_id(mod)) {
 		case 0:
 		case 4: