On Fri, Jan 19, 2024 at 01:56:54PM +0530, Maulik Shah wrote:
> Each RPMh VREG accelerator resource has 3 or 4 contiguous 4-byte aligned
> addresses associated with it. These control voltage, enable state, mode,
> and in legacy targets, voltage headroom. The current in-flight request
> checking logic looks for exact address matches. Requests for different
> addresses of the same RPMh resource as thus not detected as in-flight.
>
> Enhance the in-flight request check for VREG requests by ignoring the
> address offset. This ensures that only one request is allowed to be
> in-flight for a given VREG resource. This is needed to avoid scenarios
> where request commands are carried out by RPMh hardware out-of-order
> leading to LDO regulator over-current protection triggering.
>
> Signed-off-by: Maulik Shah <quic_mkshah@xxxxxxxxxxx>
> Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
Just noticed I commented on v1 when v2 was already out, sorry. Copy
pasting this just to keep it on the latest thread:
Two minor things:
1. Does this deserve a Fixes: tag?
2. The Signed-off-by chain here confuses me, you sent the patch
so your SOB should be last, but then that makes me believe Elliot
was the author which I don't think is reflected here (no From:
line). Please read [0] for a bit more details
[0] https://www.kernel.org/doc/html/latest/process/submitting-patches.html#developer-s-certificate-of-origin-1-1
> ---
> Changes in v2:
> - Use GENMASK() and FIELD_GET()
> - Link to v1: https://lore.kernel.org/r/20240117-rpmh-rsc-fixes-v1-1-71ee4f8f72a4@xxxxxxxxxxx
> ---
> drivers/soc/qcom/rpmh-rsc.c | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
> index a021dc71807b..e480cde783fe 100644
> --- a/drivers/soc/qcom/rpmh-rsc.c
> +++ b/drivers/soc/qcom/rpmh-rsc.c
> @@ -1,11 +1,13 @@
> // SPDX-License-Identifier: GPL-2.0
> /*
> * Copyright (c) 2016-2018, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved.
> */
>
> #define pr_fmt(fmt) "%s " fmt, KBUILD_MODNAME
>
> #include <linux/atomic.h>
> +#include <linux/bitfield.h>
> #include <linux/cpu_pm.h>
> #include <linux/delay.h>
> #include <linux/interrupt.h>
> @@ -91,6 +93,15 @@ enum {
> #define CMD_STATUS_ISSUED BIT(8)
> #define CMD_STATUS_COMPL BIT(16)
>
> +#define ACCL_TYPE(addr) FIELD_GET(GENMASK(19, 16), addr)
> +#define VREG_ADDR(addr) FIELD_GET(GENMASK(19, 4), addr)
> +
> +enum {
> + HW_ACCL_CLK = 0x3,
> + HW_ACCL_VREG,
> + HW_ACCL_BUS,
> +};
> +
> /*
> * Here's a high level overview of how all the registers in RPMH work
> * together:
> @@ -557,7 +568,15 @@ static int check_for_req_inflight(struct rsc_drv *drv, struct tcs_group *tcs,
> for_each_set_bit(j, &curr_enabled, MAX_CMDS_PER_TCS) {
> addr = read_tcs_cmd(drv, drv->regs[RSC_DRV_CMD_ADDR], i, j);
> for (k = 0; k < msg->num_cmds; k++) {
> - if (addr == msg->cmds[k].addr)
> + /*
> + * Each RPMh VREG accelerator resource has 3 or 4 contiguous 4-byte
> + * aligned addresses associated with it. Ignore the offset to check
> + * for in-flight VREG requests.
> + */
> + if (ACCL_TYPE(msg->cmds[k].addr) == HW_ACCL_VREG &&
> + VREG_ADDR(msg->cmds[k].addr) == VREG_ADDR(addr))
> + return -EBUSY;
> + else if (addr == msg->cmds[k].addr)
> return -EBUSY;
> }
> }
>
> ---
> base-commit: 943b9f0ab2cfbaea148dd6ac279957eb08b96904
> change-id: 20240117-rpmh-rsc-fixes-6c43c7051828
>
> Best regards,
> --
> Maulik Shah <quic_mkshah@xxxxxxxxxxx>
>
>
