On Tue 15 Sep 17:37 UTC 2020, Sibi Sankar wrote:
> On secure devices which support warm reset, the modem subsystem requires
> access to the mpss region to clear them out. Hence assign the mpss region
> to Q6 before MBA cold boot. This will be a nop during a modem SSR.
>
> Signed-off-by: Sibi Sankar <sibis@xxxxxxxxxxxxxx>
> ---
>
> I didn't want to add any new flags for warm reset support because
> calling xfer for mpss to q6 shouldn't have any side effects on
> platforms that don't support warm resets.
>
As discussed offline, I don't see a problem with unconditionally handing
over the ownership of the region during this time frame. So let's just
generalize the comment below a little bit and I'm happy with this
change.
Thanks,
Bjorn
> drivers/remoteproc/qcom_q6v5_mss.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
> index c401bcc263fa5..cc5b7edc02c73 100644
> --- a/drivers/remoteproc/qcom_q6v5_mss.c
> +++ b/drivers/remoteproc/qcom_q6v5_mss.c
> @@ -931,6 +931,18 @@ static int q6v5_mba_load(struct q6v5 *qproc)
> goto assert_reset;
> }
>
> + /**
> + * On secure devices which support warm reboot, the modem subsystem's cold boot is similar
> + * to an SSR sequence i.e the mba requires access to the modem memory to clear it out during
> + * Q6 cold boot. For modem SSR it will be a nop.
> + */
> + ret = q6v5_xfer_mem_ownership(qproc, &qproc->mpss_perm, false, true,
> + qproc->mpss_phys, qproc->mpss_size);
> + if (ret) {
> + dev_err(qproc->dev, "assigning Q6 access to mpss memory failed: %d\n", ret);
> + goto disable_active_clks;
> + }
> +
> /* Assign MBA image access in DDR to q6 */
> ret = q6v5_xfer_mem_ownership(qproc, &qproc->mba_perm, false, true,
> qproc->mba_phys, qproc->mba_size);
> --
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> a Linux Foundation Collaborative Project
>
