[RFC PATCH 0/2] env: sf: remove the static env_flash variable

[RFC PATCH 0/2] env: sf: remove the static env_flash variable

[Patrick Delaunay]

Proposal to cleanup the SPI device support in env/sf.c,
after the question of mail [1].

Release the SPI flash after each ENV request, so U-Boot can't have
conflict of other SPI user.

This serie can be applied on top on previous serie [2].

Drawback: possible performance issue as SPI device is probed/release
for each ENV access when several ENV opts are called.

[1] Mail "Question about env_flash variable in env/sf.c" Dec 17, 2020; 6:33pm
http://u-boot.10912.n7.nabble.com/Question-about-env-flash-variable-in-env-sf-c-tt435311.html

[2] env: sf: add support of command env erase
http://patchwork.ozlabs.org/project/uboot/list/?series=228696&state=*

Patrick



Patrick Delaunay (2):
  env: sf: add missing spi_flash_free
  env: sf: remove the static env_flash variable

 env/sf.c | 44 ++++++++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 20 deletions(-)

-- 
2.17.1

[RFC PATCH 1/2] env: sf: add missing spi_flash_free

[Patrick Delaunay]

Free the SPI resources by calling spi_flash_free() in each env sf
function to avoid issue for other SPI users.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
---

 env/sf.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/env/sf.c b/env/sf.c
index 6b61a4b8de..acbd712aef 100644
--- a/env/sf.c
+++ b/env/sf.c
@@ -149,6 +149,9 @@ static int env_sf_save(void)
 	printf("Valid environment: %d\n", (int)gd->env_valid);
 
 done:
+	spi_flash_free(env_flash);
+	env_flash = NULL;
+
 	if (saved_buffer)
 		free(saved_buffer);
 
@@ -246,6 +249,9 @@ static int env_sf_save(void)
 	puts("done\n");
 
 done:
+	spi_flash_free(env_flash);
+	env_flash = NULL;
+
 	if (saved_buffer)
 		free(saved_buffer);
 
@@ -404,6 +410,9 @@ static int env_sf_init_early(void)
 		gd->env_addr = (unsigned long)&tmp_env1->data;
 	}
 
+	spi_flash_free(env_flash);
+	env_flash = NULL;
+
 	return 0;
 err_read:
 	spi_flash_free(env_flash);
-- 
2.17.1

[RFC PATCH 2/2] env: sf: remove the static env_flash variable

[Patrick Delaunay]

As the the SPI flash is probed and is released in each ENV sf function
the env_flash no more need to be static.

This patch move this device handle as local variable of each function and
simplify the associated code (env_flash is never == NULL when
setup_flash_device is called).

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
---

 env/sf.c | 41 ++++++++++++++++++-----------------------
 1 file changed, 18 insertions(+), 23 deletions(-)

diff --git a/env/sf.c b/env/sf.c
index acbd712aef..b7cf9c64d4 100644
--- a/env/sf.c
+++ b/env/sf.c
@@ -43,9 +43,7 @@ static ulong env_new_offset	= CONFIG_ENV_OFFSET_REDUND;
 
 DECLARE_GLOBAL_DATA_PTR;
 
-static struct spi_flash *env_flash;
-
-static int setup_flash_device(void)
+static int setup_flash_device(struct spi_flash **env_flash)
 {
 #if CONFIG_IS_ENABLED(DM_SPI_FLASH)
 	struct udevice *new;
@@ -60,14 +58,11 @@ static int setup_flash_device(void)
 		return ret;
 	}
 
-	env_flash = dev_get_uclass_priv(new);
+	*env_flash = dev_get_uclass_priv(new);
 #else
-	if (env_flash)
-		spi_flash_free(env_flash);
-
-	env_flash = spi_flash_probe(CONFIG_ENV_SPI_BUS, CONFIG_ENV_SPI_CS,
-				    CONFIG_ENV_SPI_MAX_HZ, CONFIG_ENV_SPI_MODE);
-	if (!env_flash) {
+	*env_flash = spi_flash_probe(CONFIG_ENV_SPI_BUS, CONFIG_ENV_SPI_CS,
+				     CONFIG_ENV_SPI_MAX_HZ, CONFIG_ENV_SPI_MODE);
+	if (!*env_flash) {
 		env_set_default("spi_flash_probe() failed", 0);
 		return -EIO;
 	}
@@ -82,8 +77,9 @@ static int env_sf_save(void)
 	char	*saved_buffer = NULL, flag = ENV_REDUND_OBSOLETE;
 	u32	saved_size, saved_offset, sector;
 	int	ret;
+	struct spi_flash *env_flash;
 
-	ret = setup_flash_device();
+	ret = setup_flash_device(&env_flash);
 	if (ret)
 		return ret;
 
@@ -150,7 +146,6 @@ static int env_sf_save(void)
 
 done:
 	spi_flash_free(env_flash);
-	env_flash = NULL;
 
 	if (saved_buffer)
 		free(saved_buffer);
@@ -163,6 +158,7 @@ static int env_sf_load(void)
 	int ret;
 	int read1_fail, read2_fail;
 	env_t *tmp_env1, *tmp_env2;
+	struct spi_flash *env_flash;
 
 	tmp_env1 = (env_t *)memalign(ARCH_DMA_MINALIGN,
 			CONFIG_ENV_SIZE);
@@ -174,7 +170,7 @@ static int env_sf_load(void)
 		goto out;
 	}
 
-	ret = setup_flash_device();
+	ret = setup_flash_device(&env_flash);
 	if (ret)
 		goto out;
 
@@ -187,7 +183,6 @@ static int env_sf_load(void)
 				read2_fail, H_EXTERNAL);
 
 	spi_flash_free(env_flash);
-	env_flash = NULL;
 out:
 	free(tmp_env1);
 	free(tmp_env2);
@@ -201,8 +196,9 @@ static int env_sf_save(void)
 	char	*saved_buffer = NULL;
 	int	ret = 1;
 	env_t	env_new;
+	struct spi_flash *env_flash;
 
-	ret = setup_flash_device();
+	ret = setup_flash_device(&env_flash);
 	if (ret)
 		return ret;
 
@@ -250,7 +246,6 @@ static int env_sf_save(void)
 
 done:
 	spi_flash_free(env_flash);
-	env_flash = NULL;
 
 	if (saved_buffer)
 		free(saved_buffer);
@@ -262,6 +257,7 @@ static int env_sf_load(void)
 {
 	int ret;
 	char *buf = NULL;
+	struct spi_flash *env_flash;
 
 	buf = (char *)memalign(ARCH_DMA_MINALIGN, CONFIG_ENV_SIZE);
 	if (!buf) {
@@ -269,7 +265,7 @@ static int env_sf_load(void)
 		return -EIO;
 	}
 
-	ret = setup_flash_device();
+	ret = setup_flash_device(&env_flash);
 	if (ret)
 		goto out;
 
@@ -286,7 +282,6 @@ static int env_sf_load(void)
 
 err_read:
 	spi_flash_free(env_flash);
-	env_flash = NULL;
 out:
 	free(buf);
 
@@ -298,8 +293,9 @@ static int env_sf_erase(void)
 {
 	int ret;
 	env_t env;
+	struct spi_flash *env_flash;
 
-	ret = setup_flash_device();
+	ret = setup_flash_device(&env_flash);
 	if (ret)
 		return ret;
 
@@ -313,7 +309,6 @@ static int env_sf_erase(void)
 
 done:
 	spi_flash_free(env_flash);
-	env_flash = NULL;
 
 	return ret;
 }
@@ -358,6 +353,7 @@ static int env_sf_init_early(void)
 	int crc1_ok;
 	env_t *tmp_env2 = NULL;
 	env_t *tmp_env1;
+	struct spi_flash *env_flash;
 
 	/*
 	 * if malloc is not ready yet, we cannot use
@@ -375,7 +371,7 @@ static int env_sf_init_early(void)
 	if (!tmp_env1 || !tmp_env2)
 		goto out;
 
-	ret = setup_flash_device();
+	ret = setup_flash_device(&env_flash);
 	if (ret)
 		goto out;
 
@@ -411,12 +407,11 @@ static int env_sf_init_early(void)
 	}
 
 	spi_flash_free(env_flash);
-	env_flash = NULL;
 
 	return 0;
 err_read:
 	spi_flash_free(env_flash);
-	env_flash = NULL;
+
 	free(tmp_env1);
 	if (IS_ENABLED(CONFIG_SYS_REDUNDAND_ENVIRONMENT))
 		free(tmp_env2);
-- 
2.17.1

[RFC PATCH 1/2] env: sf: add missing spi_flash_free

[Tom Rini]

On Wed, Feb 24, 2021 at 11:52:35AM +0100, Patrick Delaunay wrote:

> Free the SPI resources by calling spi_flash_free() in each env sf
> function to avoid issue for other SPI users.
> 
> Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>

Applied to u-boot/master, thanks!

-- 
Tom
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[RFC PATCH 2/2] env: sf: remove the static env_flash variable

[Tom Rini]

On Wed, Feb 24, 2021 at 11:52:36AM +0100, Patrick Delaunay wrote:

> As the the SPI flash is probed and is released in each ENV sf function
> the env_flash no more need to be static.
> 
> This patch move this device handle as local variable of each function and
> simplify the associated code (env_flash is never == NULL when
> setup_flash_device is called).
> 
> Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>

Applied to u-boot/master, thanks!

-- 
Tom
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