2020-04-09 16:08:27

by Rafał Hibner

Subject: [PATCH] spi: spi-axi-spi-engine: Access register after clock initialization

Move register access after clock initialization.
Clock "s_axi_aclk" is needed for register access. Without the clock running
AXI bus hangs and causes kernel freeze.

Cc: Alexandru Ardelean <[email protected]>
Signed-off-by: Rafał Hibner <[email protected]>
---
drivers/spi/spi-axi-spi-engine.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index eb9b78a90d..af86e6d6e1 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -489,22 +489,6 @@ static int spi_engine_probe(struct platform_device *pdev)

spin_lock_init(&spi_engine->lock);

- spi_engine->base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(spi_engine->base)) {
- ret = PTR_ERR(spi_engine->base);
- goto err_put_master;
- }
-
- version = readl(spi_engine->base + SPI_ENGINE_REG_VERSION);
- if (SPI_ENGINE_VERSION_MAJOR(version) != 1) {
- dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%c\n",
- SPI_ENGINE_VERSION_MAJOR(version),
- SPI_ENGINE_VERSION_MINOR(version),
- SPI_ENGINE_VERSION_PATCH(version));
- ret = -ENODEV;
- goto err_put_master;
- }
-
spi_engine->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
if (IS_ERR(spi_engine->clk)) {
ret = PTR_ERR(spi_engine->clk);
@@ -525,6 +509,22 @@ static int spi_engine_probe(struct platform_device *pdev)
if (ret)
goto err_clk_disable;

+ spi_engine->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(spi_engine->base)) {
+ ret = PTR_ERR(spi_engine->base);
+ goto err_ref_clk_disable;
+ }
+
+ version = readl(spi_engine->base + SPI_ENGINE_REG_VERSION);
+ if (SPI_ENGINE_VERSION_MAJOR(version) != 1) {
+ dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%c\n",
+ SPI_ENGINE_VERSION_MAJOR(version),
+ SPI_ENGINE_VERSION_MINOR(version),
+ SPI_ENGINE_VERSION_PATCH(version));
+ ret = -ENODEV;
+ goto err_ref_clk_disable;
+ }
+
writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET);
writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
--
2.24.1

2020-04-09 17:31:00

by Alexandru Ardelean

Subject: Re: [PATCH] spi: spi-axi-spi-engine: Access register after clock initialization

On Thu, 2020-04-09 at 17:56 +0200, Rafał Hibner wrote:
> [External]
>
> Move register access after clock initialization.
> Clock "s_axi_aclk" is needed for register access. Without the clock running
> AXI bus hangs and causes kernel freeze.

this patch should have been marked as V2
the easiest way to apply V2 tags, is to run 'git format-patch -v2'
[or -v3 for 3rd version]

no idea if you need to re-send this;
i guess it's up to the maintainer;
maybe try to remember this when re-sending patches, each re-send is an increment

also, it's a good idea to add a changelog right after the --- line
that line doesn't get applied;

other than that:

Reviewed-by: Alexandru Ardelean <[email protected]>

>
> Cc: Alexandru Ardelean <[email protected]>
> Signed-off-by: Rafał Hibner <[email protected]>
> ---

so here, something like:
Changelog v1 -> v2:
* re-send in plain-text format


> drivers/spi/spi-axi-spi-engine.c | 32 ++++++++++++++++----------------
> 1 file changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-
> engine.c
> index eb9b78a90d..af86e6d6e1 100644
> --- a/drivers/spi/spi-axi-spi-engine.c
> +++ b/drivers/spi/spi-axi-spi-engine.c
> @@ -489,22 +489,6 @@ static int spi_engine_probe(struct platform_device *pdev)
>
> spin_lock_init(&spi_engine->lock);
>
> - spi_engine->base = devm_platform_ioremap_resource(pdev, 0);
> - if (IS_ERR(spi_engine->base)) {
> - ret = PTR_ERR(spi_engine->base);
> - goto err_put_master;
> - }
> -
> - version = readl(spi_engine->base + SPI_ENGINE_REG_VERSION);
> - if (SPI_ENGINE_VERSION_MAJOR(version) != 1) {
> - dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%c\n",
> - SPI_ENGINE_VERSION_MAJOR(version),
> - SPI_ENGINE_VERSION_MINOR(version),
> - SPI_ENGINE_VERSION_PATCH(version));
> - ret = -ENODEV;
> - goto err_put_master;
> - }
> -
> spi_engine->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
> if (IS_ERR(spi_engine->clk)) {
> ret = PTR_ERR(spi_engine->clk);
> @@ -525,6 +509,22 @@ static int spi_engine_probe(struct platform_device *pdev)
> if (ret)
> goto err_clk_disable;
>
> + spi_engine->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(spi_engine->base)) {
> + ret = PTR_ERR(spi_engine->base);
> + goto err_ref_clk_disable;
> + }
> +
> + version = readl(spi_engine->base + SPI_ENGINE_REG_VERSION);
> + if (SPI_ENGINE_VERSION_MAJOR(version) != 1) {
> + dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%c\n",
> + SPI_ENGINE_VERSION_MAJOR(version),
> + SPI_ENGINE_VERSION_MINOR(version),
> + SPI_ENGINE_VERSION_PATCH(version));
> + ret = -ENODEV;
> + goto err_ref_clk_disable;
> + }
> +
> writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET);
> writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
> writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);