[PATCH v3 04/10] soc: ti: k3-navss-ringacc: Fix reset ring API

[Sverdlin, Alexander]

Hi Chintan, Vignesh,

On Fri, 2024-07-05 at 10:20 +0530, Chintan Vankar wrote:
> From: Vignesh Raghavendra <vigneshr at ti.com>
> 
> Expectation of k3_ringacc_ring_reset_raw() is to reset the ring to
> requested size and not to 0. Fix this.
> 
> Signed-off-by: Vignesh Raghavendra <vigneshr at ti.com>
> Signed-off-by: Siddharth Vadapalli <s-vadapalli at ti.com>
> Signed-off-by: Chintan Vankar <c-vankar at ti.com>
> ---
> 
> Link to v2:
> https://lore.kernel.org/r/20240425120822.2048012-5-c-vankar@ti.com/
> 
> Changes from v2 to v3:
> - No changes.
> 
>  drivers/soc/ti/k3-navss-ringacc-u-boot.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/ti/k3-navss-ringacc-u-boot.c b/drivers/soc/ti/k3-navss-ringacc-u-boot.c
> index f958239c2a..5d650b9de7 100644
> --- a/drivers/soc/ti/k3-navss-ringacc-u-boot.c
> +++ b/drivers/soc/ti/k3-navss-ringacc-u-boot.c
> @@ -25,9 +25,16 @@ struct k3_nav_ring_cfg_regs {
>  #define KNAV_RINGACC_CFG_RING_SIZE_ELSIZE_MASK		GENMASK(26, 24)
>  #define KNAV_RINGACC_CFG_RING_SIZE_ELSIZE_SHIFT		(24)
>  
> +#define KNAV_RINGACC_CFG_RING_SIZE_MASK			GENMASK(15, 0)
> +
>  static void k3_ringacc_ring_reset_raw(struct k3_nav_ring *ring)
>  {
> -	writel(0, &ring->cfg->size);
> +	u32 reg;
> +
> +	reg = readl(&ring->cfg->size);
> +	reg &= KNAV_RINGACC_CFG_RING_SIZE_MASK;

should it actually be "reg &= ~KNAV_RINGACC_CFG_RING_SIZE_MASK;"?
Otherwise you could potentially bump the size to some number higher than ring->size
if you "OR" ring->size with something lower than ring->size and ring->size is not
N^2-1?

> +	reg |= ring->size;
> +	writel(reg, &ring->cfg->size);
>  }
>  
>  static void k3_ringacc_ring_reconfig_qmode_raw(struct k3_nav_ring *ring, enum k3_nav_ring_mode mode)

-- 
Alexander Sverdlin
Siemens AG
www.siemens.com