On Thu, 19 Aug 2021 12:53:12 +0100,
Maulik Shah <mkshah@xxxxxxxxxxxxxx> wrote:
>
> Currently tail marker is moving along with parent domain
> irq data. Fix this to initialize only once from where all
> parent domain needs trimming.
>
> Also correct the valid irq chip check.
>
> Signed-off-by: Maulik Shah <mkshah@xxxxxxxxxxxxxx>
> ---
> kernel/irq/irqdomain.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index 19e83e9..9f6187b 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -1235,7 +1235,7 @@ static int irq_domain_trim_hierarchy(unsigned int virq)
> */
> for (irqd = irq_data->parent_data; irqd; irq_data = irqd, irqd = irqd->parent_data) {
> /* Can't have a valid irqchip after a trim marker */
> - if (irqd->chip && tail)
> + if (!IS_ERR(irqd->chip) && tail)
> return -EINVAL;
>
> /* Can't have an empty irqchip before a trim marker */
> @@ -1247,7 +1247,8 @@ static int irq_domain_trim_hierarchy(unsigned int virq)
> if (PTR_ERR(irqd->chip) != -ENOTCONN)
> return -EINVAL;
>
> - tail = irq_data;
> + if (!tail)
> + tail = irq_data;
> }
> }
I think you have the wrong end of the stick. 'tail' represent the
*unique* point in the hierarchy where you can have a trim marker:
(1) If there is a valid irqchip after a trim marker, this is wrong
(2) If there is a trim marker after another trim marker, this is wrong
(3) If there is a NULL irqchip before a trim marker, this is wrong
(4) If there is an error that isn't a trim marker, this is wrong
(1) and (2) are captured by:
if (irqd->chip && tail)
(3) is captured by:
if (!irqd->chip && !tail)
(4) is captured by:
if (IS_ERR(irqd->chip)) {
/* Only -ENOTCONN is a valid trim marker */
if (PTR_ERR(irqd->chip) != -ENOTCONN)
The expected usage is that:
- there is a single potential trim marker in the hierarchy
- all the irqd->chip pointers below the marker are NULL
- all the irqd->chip before the marker are neither NULL nor an error
I don't see any bug here.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
