On Mon, Dec 30, 2024 at 01:24:25PM +0530, Mukesh Ojha wrote:
> For some SoCs, boot firmware is using the same IPCC instance used
> by Linux and it has kept CLEAR_ON_RECV_RD set which basically means
> interrupt pending registers are cleared when RECV_ID is read and the
> register automatically updates to the next pending interrupt/client
> status based on priority.
>
> Clear the CLEAR_ON_RECV_RD if it is set from the boot firmware.
>
Any user visible implications due to this?
> Signed-off-by: Mukesh Ojha <mukesh.ojha@xxxxxxxxxxxxxxxx>
> ---
> Change in v2:
> - Corrected email id in the Sob.
>
> drivers/mailbox/qcom-ipcc.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/mailbox/qcom-ipcc.c b/drivers/mailbox/qcom-ipcc.c
> index 14c7907c6632..0b17a38ea6bf 100644
> --- a/drivers/mailbox/qcom-ipcc.c
> +++ b/drivers/mailbox/qcom-ipcc.c
> @@ -14,6 +14,7 @@
> #include <dt-bindings/mailbox/qcom-ipcc.h>
>
> /* IPCC Register offsets */
> +#define IPCC_REG_CONFIG 0x08
> #define IPCC_REG_SEND_ID 0x0c
> #define IPCC_REG_RECV_ID 0x10
> #define IPCC_REG_RECV_SIGNAL_ENABLE 0x14
> @@ -21,6 +22,7 @@
> #define IPCC_REG_RECV_SIGNAL_CLEAR 0x1c
> #define IPCC_REG_CLIENT_CLEAR 0x38
>
> +#define IPCC_CLEAR_ON_RECV_RD BIT(0)
> #define IPCC_SIGNAL_ID_MASK GENMASK(15, 0)
> #define IPCC_CLIENT_ID_MASK GENMASK(31, 16)
>
> @@ -274,6 +276,7 @@ static int qcom_ipcc_pm_resume(struct device *dev)
> static int qcom_ipcc_probe(struct platform_device *pdev)
> {
> struct qcom_ipcc *ipcc;
> + u32 config_value;
> static int id;
> char *name;
> int ret;
> @@ -288,6 +291,19 @@ static int qcom_ipcc_probe(struct platform_device *pdev)
> if (IS_ERR(ipcc->base))
> return PTR_ERR(ipcc->base);
>
> + /*
> + * It is possible that boot firmware is using the same IPCC instance
> + * as of the HLOS and it has kept CLEAR_ON_RECV_RD set which basically
> + * means Interrupt pending registers are cleared when RECV_ID is read.
> + * The register automatically updates to the next pending interrupt/client
> + * status based on priority.
> + */
> + config_value = readl(ipcc->base + IPCC_REG_CONFIG);
> + if (config_value & IPCC_CLEAR_ON_RECV_RD) {
Can't you just clear this bit always?
- Mani
--
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