On Mon, Sep 08, 2025 at 10:42:10AM +0530, Ekansh Gupta wrote: > > > On 9/2/2025 9:42 AM, Dmitry Baryshkov wrote: > > 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). > Ack. > > > >> 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. > I'm not sure if it could be called a bug fix as there is no problem with > existing mask. > The problem is seen only when polling mode is added.
This sounds like a perfect part of the commit message. > > > >> Update the context mask to ensure a hole > >> which won't get populated, ensuring polling mode works as expected. > >> > >> Signed-off-by: Ekansh Gupta <[email protected]> > >> --- > >> 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 > Ack. > > > >> 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
