* [PATCH] simplefb: Separate clk / regulator get and enable steps
2016-11-04 14:45 ` [PATCH] simplefb: Separate clk / regulator get and enable steps Hans de Goede
@ 2017-01-11 15:07 ` Bartlomiej Zolnierkiewicz
0 siblings, 0 replies; 2+ messages in thread
From: Bartlomiej Zolnierkiewicz @ 2017-01-11 15:07 UTC (permalink / raw)
To: linux-arm-kernel
Hi,
On Friday, November 04, 2016 03:45:07 PM Hans de Goede wrote:
> Currently when a simplefb needs both clocks and regulators and one
> of the regulators returns -EPROBE_DEFER when we try to get it, we end
> up disabling the clocks. This causes the screen to go blank; and in some
> cases my cause hardware state to be lost resulting in the framebuffer not
> working at all.
>
> This commit splits the get and enable steps and only enables
> clocks and regulators after successfully getting all of them,
> fixing the disabling of the clocks which were left enabled by
> the firmware setting up the simplefb.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Thanks, patch queued for 4.11.
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
> ---
> drivers/video/fbdev/simplefb.c | 56 ++++++++++++++++++++++++++++++------------
> 1 file changed, 40 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c
> index 61f799a..a3c44ec 100644
> --- a/drivers/video/fbdev/simplefb.c
> +++ b/drivers/video/fbdev/simplefb.c
> @@ -180,10 +180,12 @@ static int simplefb_parse_pd(struct platform_device *pdev,
> struct simplefb_par {
> u32 palette[PSEUDO_PALETTE_SIZE];
> #if defined CONFIG_OF && defined CONFIG_COMMON_CLK
> + bool clks_enabled;
> unsigned int clk_count;
> struct clk **clks;
> #endif
> #if defined CONFIG_OF && defined CONFIG_REGULATOR
> + bool regulators_enabled;
> u32 regulator_count;
> struct regulator **regulators;
> #endif
> @@ -208,12 +210,12 @@ struct simplefb_par {
> * the fb probe will not help us much either. So just complain and carry on,
> * and hope that the user actually gets a working fb at the end of things.
> */
> -static int simplefb_clocks_init(struct simplefb_par *par,
> - struct platform_device *pdev)
> +static int simplefb_clocks_get(struct simplefb_par *par,
> + struct platform_device *pdev)
> {
> struct device_node *np = pdev->dev.of_node;
> struct clk *clock;
> - int i, ret;
> + int i;
>
> if (dev_get_platdata(&pdev->dev) || !np)
> return 0;
> @@ -244,6 +246,14 @@ static int simplefb_clocks_init(struct simplefb_par *par,
> par->clks[i] = clock;
> }
>
> + return 0;
> +}
> +
> +static void simplefb_clocks_enable(struct simplefb_par *par,
> + struct platform_device *pdev)
> +{
> + int i, ret;
> +
> for (i = 0; i < par->clk_count; i++) {
> if (par->clks[i]) {
> ret = clk_prepare_enable(par->clks[i]);
> @@ -256,8 +266,7 @@ static int simplefb_clocks_init(struct simplefb_par *par,
> }
> }
> }
> -
> - return 0;
> + par->clks_enabled = true;
> }
>
> static void simplefb_clocks_destroy(struct simplefb_par *par)
> @@ -269,7 +278,8 @@ static void simplefb_clocks_destroy(struct simplefb_par *par)
>
> for (i = 0; i < par->clk_count; i++) {
> if (par->clks[i]) {
> - clk_disable_unprepare(par->clks[i]);
> + if (par->clks_enabled)
> + clk_disable_unprepare(par->clks[i]);
> clk_put(par->clks[i]);
> }
> }
> @@ -277,8 +287,10 @@ static void simplefb_clocks_destroy(struct simplefb_par *par)
> kfree(par->clks);
> }
> #else
> -static int simplefb_clocks_init(struct simplefb_par *par,
> +static int simplefb_clocks_get(struct simplefb_par *par,
> struct platform_device *pdev) { return 0; }
> +static void simplefb_clocks_enable(struct simplefb_par *par,
> + struct platform_device *pdev) { }
> static void simplefb_clocks_destroy(struct simplefb_par *par) { }
> #endif
>
> @@ -305,14 +317,14 @@ static void simplefb_clocks_destroy(struct simplefb_par *par) { }
> * the fb probe will not help us much either. So just complain and carry on,
> * and hope that the user actually gets a working fb at the end of things.
> */
> -static int simplefb_regulators_init(struct simplefb_par *par,
> - struct platform_device *pdev)
> +static int simplefb_regulators_get(struct simplefb_par *par,
> + struct platform_device *pdev)
> {
> struct device_node *np = pdev->dev.of_node;
> struct property *prop;
> struct regulator *regulator;
> const char *p;
> - int count = 0, i = 0, ret;
> + int count = 0, i = 0;
>
> if (dev_get_platdata(&pdev->dev) || !np)
> return 0;
> @@ -354,6 +366,14 @@ static int simplefb_regulators_init(struct simplefb_par *par,
> }
> par->regulator_count = i;
>
> + return 0;
> +}
> +
> +static void simplefb_regulators_enable(struct simplefb_par *par,
> + struct platform_device *pdev)
> +{
> + int i, ret;
> +
> /* Enable all the regulators */
> for (i = 0; i < par->regulator_count; i++) {
> ret = regulator_enable(par->regulators[i]);
> @@ -365,15 +385,14 @@ static int simplefb_regulators_init(struct simplefb_par *par,
> par->regulators[i] = NULL;
> }
> }
> -
> - return 0;
> + par->regulators_enabled = true;
> }
>
> static void simplefb_regulators_destroy(struct simplefb_par *par)
> {
> int i;
>
> - if (!par->regulators)
> + if (!par->regulators || !par->regulators_enabled)
> return;
>
> for (i = 0; i < par->regulator_count; i++)
> @@ -381,8 +400,10 @@ static void simplefb_regulators_destroy(struct simplefb_par *par)
> regulator_disable(par->regulators[i]);
> }
> #else
> -static int simplefb_regulators_init(struct simplefb_par *par,
> +static int simplefb_regulators_get(struct simplefb_par *par,
> struct platform_device *pdev) { return 0; }
> +static void simplefb_regulators_enable(struct simplefb_par *par,
> + struct platform_device *pdev) { }
> static void simplefb_regulators_destroy(struct simplefb_par *par) { }
> #endif
>
> @@ -453,14 +474,17 @@ static int simplefb_probe(struct platform_device *pdev)
> }
> info->pseudo_palette = par->palette;
>
> - ret = simplefb_clocks_init(par, pdev);
> + ret = simplefb_clocks_get(par, pdev);
> if (ret < 0)
> goto error_unmap;
>
> - ret = simplefb_regulators_init(par, pdev);
> + ret = simplefb_regulators_get(par, pdev);
> if (ret < 0)
> goto error_clocks;
>
> + simplefb_clocks_enable(par, pdev);
> + simplefb_regulators_enable(par, pdev);
> +
> dev_info(&pdev->dev, "framebuffer at 0x%lx, 0x%x bytes, mapped to 0x%p\n",
> info->fix.smem_start, info->fix.smem_len,
> info->screen_base);
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