[PATCH v3] power: domain: ti: fix ti_pd_get() to return after verifying transition

[Hrushikesh Salunke]

On 18/11/25 17:50, Siddharth Vadapalli wrote:
> The helper function "ti_pd_get()" is responsible for powering on a
> domain if it is powered off. In the current implementation, if a power
> domain is determined to be powered off - no prior users and the PDCTL
> register indicates that the user desired state is OFF, then powering on
> the domain constitutes setting 'PDCTL_STATE_ON' field of the PDCTL
> register.
> 
> While the current implementation indeed requests the power domain to be
> transition to the ON state, the helper function "ti_pd_get()" doesn't
> verify that the power domain has 'transitioned' to the ON state before
> returning to its caller. As a result, it is possible that the device(s)
> belonging to the power domain may be accessed before it is truly powered
> on, leading to a bus abort.
> 
> Fix this by waiting for the power domain to transition to the ON state
> by using "ti_pd_wait()" before returning from "ti_pd_get()".
> 
> Fixes: 144464bd2c67 ("power: domain: Introduce driver for raw TI K3 PDs")
> Signed-off-by: Siddharth Vadapalli <s-vadapalli at ti.com>
> ---
> 
> Hello,
> 
> This patch is based on commit
> 91861e5a30d Merge tag 'u-boot-stm32-20251117' of https://source.denx.de/u-boot/custodians/u-boot-stm
> of the master branch of U-Boot.
> 
> v2 of this patch is at:
> https://lore.kernel.org/r/20251114150243.96429-1-s-vadapalli@ti.com/
> Changes since v2:
> - Rebased patch on latest master.
> - Fixed the parameter passed to ti_pd_wait().
> 
> Patch has been tested for PCIe Boot on J784S4 SoC and the 1 millisecond
> delay is no longer required in the pcie_cdns_ti_ep.c driver with this
> patch.

Tested the patch on J784s4. Following are the test logs.

Logs : 
https://gist.github.com/hrushikesh221/d21c33bcb88f7a271ae5aba66954cdb2

Tested-by: Hrushikesh Salunke <h-salunke at ti.com>

> 
> Regards,
> Siddharth.
> 
>   drivers/power/domain/ti-power-domain.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/power/domain/ti-power-domain.c b/drivers/power/domain/ti-power-domain.c
> index c3519307340..a554e659392 100644
> --- a/drivers/power/domain/ti-power-domain.c
> +++ b/drivers/power/domain/ti-power-domain.c
> @@ -227,7 +227,7 @@ static int ti_pd_get(struct ti_pd *pd)
>   
>   	pd_write(pdctl, pd, PSC_PDCTL);
>   
> -	return 0;
> +	return ti_pd_wait(pd);
>   }
>   
>   static int ti_pd_put(struct ti_pd *pd)