Hi Stefan,
On 24-11-02, Stefan Wahren wrote:
> The recent introduction of reset control in pwrseq_simple introduced
> a regression for platforms without RESET_CONTROLLER support, because
This is what I was afraid of :/
> devm_reset_control_get_optional_shared() would return NULL and make all
> resets no-ops. Instead of enforcing this dependency rely on this behavior
> to determine reset support. As a benefit we can get the rid of the
> use_reset flag.
>
> Fixes: 73bf4b7381f7 ("mmc: pwrseq_simple: add support for one reset control")
> Signed-off-by: Stefan Wahren <wahrenst@xxxxxxx>
> ---
> drivers/mmc/core/pwrseq_simple.c | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
> Hi,
> will trying to reproduce the Rpi 4 regression from here [1], I found
> the issue above. I'm pretty sure the Rpi 4 regression is caused by the same
> commit. Unfortunately I wasn't able to reproduce it.
>
> [1] - https://lore.kernel.org/linux-next/6724d7d5.170a0220.1281e9.910a@xxxxxxxxxxxxx/T/#u
>
> diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
> index 24e4e63a5dc8..b8782727750e 100644
> --- a/drivers/mmc/core/pwrseq_simple.c
> +++ b/drivers/mmc/core/pwrseq_simple.c
> @@ -32,7 +32,6 @@ struct mmc_pwrseq_simple {
> struct clk *ext_clk;
> struct gpio_descs *reset_gpios;
> struct reset_control *reset_ctrl;
> - bool use_reset;
> };
>
> #define to_pwrseq_simple(p) container_of(p, struct mmc_pwrseq_simple, pwrseq)
> @@ -71,7 +70,7 @@ static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
> pwrseq->clk_enabled = true;
> }
>
> - if (pwrseq->use_reset) {
> + if (pwrseq->reset_ctrl) {
> reset_control_deassert(pwrseq->reset_ctrl);
> reset_control_assert(pwrseq->reset_ctrl);
> } else
> @@ -82,7 +81,7 @@ static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
> {
> struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
>
> - if (pwrseq->use_reset)
> + if (pwrseq->reset_ctrl)
> reset_control_deassert(pwrseq->reset_ctrl);
> else
> mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
> @@ -95,7 +94,7 @@ static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
> {
> struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
>
> - if (pwrseq->use_reset)
> + if (pwrseq->reset_ctrl)
> reset_control_assert(pwrseq->reset_ctrl);
> else
> mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
> @@ -137,15 +136,14 @@ static int mmc_pwrseq_simple_probe(struct platform_device *pdev)
> return dev_err_probe(dev, PTR_ERR(pwrseq->ext_clk), "external clock not ready\n");
>
> ngpio = of_count_phandle_with_args(dev->of_node, "reset-gpios", "#gpio-cells");
> - if (ngpio == 1)
> - pwrseq->use_reset = true;
> -
> - if (pwrseq->use_reset) {
> + if (ngpio == 1) {
> pwrseq->reset_ctrl = devm_reset_control_get_optional_shared(dev, NULL);
> if (IS_ERR(pwrseq->reset_ctrl))
> return dev_err_probe(dev, PTR_ERR(pwrseq->reset_ctrl),
> "reset control not ready\n");
> - } else {
> + }
> +
Can we add a comment like:
/*
* Fallback to gpio based reset control in case of multiple reset lines
* are specified or the platform doesn't have support for RESET at all.
*/
Regards,
Marco
> + if (!pwrseq->reset_ctrl) {
> pwrseq->reset_gpios = devm_gpiod_get_array(dev, "reset", GPIOD_OUT_HIGH);
> if (IS_ERR(pwrseq->reset_gpios) &&
> PTR_ERR(pwrseq->reset_gpios) != -ENOENT &&
> --
> 2.34.1
>
>
