On Mon, Sep 01, 2025 at 11:03:35AM +0530, Ekansh Gupta wrote: > Current fastrpc message context uses a 12-bit mask where the upper > 8 bits are context ID from idr_alloc_cyclic and the lower 4 bits > represent PD type. This design works for normal fastrpc calls but
FastRPC (here and in several other places). > doesn't work as expected for polling mode. To enable polling mode > support from DSP(DSP writes to poll memory), DSP expects a 16-bit > context where the upper 8 bits are context ID, the lower 4 bits are > PD type and the 5th bit from the end denotes async mode(not yet > upstreamed). If this bit is set, DSP disables polling. With the > current design, odd context IDs set this bit, causing DSP to skip > poll memory updates. This looks like a description of a bugfix. In such a case, move it to the start of the series, add necessary tatgs and change commit message accordingly. > Update the context mask to ensure a hole > which won't get populated, ensuring polling mode works as expected. > > Signed-off-by: Ekansh Gupta <ekansh.gu...@oss.qualcomm.com> > --- > drivers/misc/fastrpc.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c > index 0991ac487192..57e118de6e4a 100644 > --- a/drivers/misc/fastrpc.c > +++ b/drivers/misc/fastrpc.c > @@ -37,7 +37,7 @@ > #define FASTRPC_CTX_MAX (256) > #define FASTRPC_INIT_HANDLE 1 > #define FASTRPC_DSP_UTILITIES_HANDLE 2 > -#define FASTRPC_CTXID_MASK (0xFF0) > +#define FASTRPC_CTXID_MASK (0xFF00) > #define INIT_FILELEN_MAX (2 * 1024 * 1024) > #define INIT_FILE_NAMELEN_MAX (128) > #define FASTRPC_DEVICE_NAME "fastrpc" > @@ -487,7 +487,7 @@ static void fastrpc_context_free(struct kref *ref) > fastrpc_buf_free(ctx->buf); > > spin_lock_irqsave(&cctx->lock, flags); > - idr_remove(&cctx->ctx_idr, ctx->ctxid >> 4); > + idr_remove(&cctx->ctx_idr, ctx->ctxid >> 8); #define magic value > spin_unlock_irqrestore(&cctx->lock, flags); > > kfree(ctx->maps); > @@ -623,7 +623,7 @@ static struct fastrpc_invoke_ctx *fastrpc_context_alloc( > spin_unlock_irqrestore(&cctx->lock, flags); > goto err_idr; > } > - ctx->ctxid = ret << 4; > + ctx->ctxid = ret << 8; > spin_unlock_irqrestore(&cctx->lock, flags); > > kref_init(&ctx->refcount); > @@ -2449,7 +2449,7 @@ static int fastrpc_rpmsg_callback(struct rpmsg_device > *rpdev, void *data, > if (len < sizeof(*rsp)) > return -EINVAL; > > - ctxid = ((rsp->ctx & FASTRPC_CTXID_MASK) >> 4); > + ctxid = ((rsp->ctx & FASTRPC_CTXID_MASK) >> 8); > > spin_lock_irqsave(&cctx->lock, flags); > ctx = idr_find(&cctx->ctx_idr, ctxid); > -- > 2.34.1 > -- With best wishes Dmitry
