Re: [PATCH 3/7] clk: zynqmp: Warn user if clock user are more than allowed

Michael Tretter
2019-11-21T14:31:48Z

On Tue, 12 Nov 2019 05:16:16 -0800, Rajan Vaja wrote:
> Warn user if clock is used by more than allowed devices.
> This check is done by firmware and returns respective
> error code. Upon receiving error code for excessive user,
> warn user for the same.
>
> This change is done to restrict VPLL use count. It is
> assumed that VPLL is used by one user only.
>
> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
> Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
> ---
> drivers/clk/zynqmp/pll.c | 9 ++++++---
> drivers/firmware/xilinx/zynqmp.c | 2 ++
> include/linux/firmware/xlnx-zynqmp.h | 1 +
> 3 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/zynqmp/pll.c b/drivers/clk/zynqmp/pll.c
> index a541397..2f4ccaa 100644
> --- a/drivers/clk/zynqmp/pll.c
> +++ b/drivers/clk/zynqmp/pll.c
> @@ -188,9 +188,12 @@ static int zynqmp_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> frac = (parent_rate * f) / FRAC_DIV;
>
> ret = eemi_ops->clock_setdivider(clk_id, m);
> - if (ret)
> - pr_warn_once("%s() set divider failed for %s, ret = %d\n",
> - __func__, clk_name, ret);
> + if (ret) {
> + if (ret == -EUSERS)
> + WARN(1, "More than allowed devices are using the %s, which is forbidden\n", clk_name);
> + pr_err("%s() set divider failed for %s, ret = %d\n",
> + __func__, clk_name, ret);
> + }

In case of -EUSERS this prints the warning and the error. This seems a
bit excessive to me. Isn't it enough to leave the existing
pr_warn_once() for the new error code? If not, then add a new warning
for the -EUSERS error, but leave the existing warning as it is.

Michael

>
> eemi_ops->ioctl(0, IOCTL_SET_PLL_FRAC_DATA, clk_id, f, NULL);
>
> diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
> index 0137bf3..ecc339d 100644
> --- a/drivers/firmware/xilinx/zynqmp.c
> +++ b/drivers/firmware/xilinx/zynqmp.c
> @@ -53,6 +53,8 @@ static int zynqmp_pm_ret_code(u32 ret_status)
> return -EACCES;
> case XST_PM_ABORT_SUSPEND:
> return -ECANCELED;
> + case XST_PM_MULT_USER:
> + return -EUSERS;
> case XST_PM_INTERNAL:
> case XST_PM_CONFLICT:
> case XST_PM_INVALID_NODE:
> diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
> index 25bedd2..f019d1c 100644
> --- a/include/linux/firmware/xlnx-zynqmp.h
> +++ b/include/linux/firmware/xlnx-zynqmp.h
> @@ -96,6 +96,7 @@ enum pm_ret_status {
> XST_PM_INVALID_NODE,
> XST_PM_DOUBLE_REQ,
> XST_PM_ABORT_SUSPEND,
> + XST_PM_MULT_USER = 2008,
> };
>
> enum pm_ioctl_id {