On 23-09-2026 14:09, Vinayak Katoch wrote: > For ADSP, only a limited number of FastRPC context banks (CBs) are > available. Each CB supports a single session, which means only a few > processes can run on ADSP simultaneously. If all sessions are consumed > by fastrpc daemons, no session remains available when a user application > starts, causing the application to fail. > > To work around this, qcom,nsessions = <5> was set in DT to duplicate > sessions inline during fastrpc_cb_init(). This policy does not belong > in DT and should be handled at the driver level instead. > > Remove the qcom,nsessions DT property read and the per-CB duplication > logic from fastrpc_cb_init(). After all context banks have been > initialised in fastrpc_rpmsg_probe(), append FASTRPC_DUP_SESSIONS (4) > copies of the last session for the ADSP domain. > > Signed-off-by: Vinayak Katoch <[email protected]> > --- > drivers/misc/fastrpc.c | 29 +++++++++++++++++------------ > 1 file changed, 17 insertions(+), 12 deletions(-) > > diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c > index f20d3e5ecc81..b29c1fd00de2 100644 > --- a/drivers/misc/fastrpc.c > +++ b/drivers/misc/fastrpc.c > @@ -34,6 +34,7 @@ > #define CDSP_DOMAIN_ID (3) > #define GDSP_DOMAIN_ID (4) > #define FASTRPC_MAX_SESSIONS 14 > +#define FASTRPC_DUP_SESSIONS 4 add some comment here> #define FASTRPC_MAX_VMIDS 16 > #define FASTRPC_ALIGN 128 > #define FASTRPC_MAX_FDLIST 16 > @@ -2338,7 +2339,6 @@ static int fastrpc_cb_init(struct platform_device *pdev) > struct fastrpc_channel_ctx *cctx; > struct fastrpc_session_ctx *sess; > struct device *dev = &pdev->dev; > - int i, sessions = 0; > unsigned long flags; > u32 dma_bits; > u32 sid = 0; > @@ -2348,7 +2348,6 @@ static int fastrpc_cb_init(struct platform_device *pdev) > if (!cctx) > return -EINVAL; > > - of_property_read_u32(dev->of_node, "qcom,nsessions", &sessions); > if (of_property_read_u32(dev->of_node, "reg", &sid)) > dev_info(dev, "FastRPC Session ID not specified in DT\n"); > > @@ -2369,16 +2368,6 @@ static int fastrpc_cb_init(struct platform_device > *pdev) > if (cctx->domain_id == CDSP_DOMAIN_ID) > dma_bits = cctx->soc_data->dma_addr_bits_cdsp; > > - if (sessions > 0) { > - struct fastrpc_session_ctx *dup_sess; > - > - for (i = 1; i < sessions; i++) { > - if (cctx->sesscount >= FASTRPC_MAX_SESSIONS) > - break; > - dup_sess = &cctx->session[cctx->sesscount++]; > - memcpy(dup_sess, sess, sizeof(*dup_sess)); > - } > - } > spin_unlock_irqrestore(&cctx->lock, flags); > rc = dma_set_mask(dev, DMA_BIT_MASK(dma_bits)); > if (rc) { > @@ -2669,6 +2658,22 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device > *rpdev) > if (err) > goto err_deregister_fdev; > > + if (data->domain_id == ADSP_DOMAIN_ID && data->sesscount > 0) { > + struct fastrpc_session_ctx *last_sess; > + struct fastrpc_session_ctx *dup_sess; > + unsigned long flags; > + > + spin_lock_irqsave(&data->lock, flags); > + last_sess = &data->session[data->sesscount - 1]; > + for (i = 0; i < FASTRPC_DUP_SESSIONS; i++) { > + if (data->sesscount >= FASTRPC_MAX_SESSIONS) > + break; > + dup_sess = &data->session[data->sesscount++]; > + memcpy(dup_sess, last_sess, sizeof(*dup_sess)); > + } > + spin_unlock_irqrestore(&data->lock, flags); > + } > + > return 0; > > err_deregister_fdev: >
