Re: [PATCH] remoteproc: qcom: pas: pass no resource table when the firmware has none

[Mukesh Ojha]

On Mon, Oct 05, 2026 at 11:01:24PM +0200, Jorge Ramirez wrote:
> On 05/10/26 21:42:24, Mukesh Ojha wrote:
> > On Mon, Oct 05, 2026 at 02:54:00PM +0200, Jorge Ramirez-Ortiz wrote:
> > > The firmware resource table is passed to the PAS backend even when the
> > > firmware carries none. This only works on the first boot, while the
> > > cached pointer and its size are both zero.
> > > 
> > > Stopping the remote processor, or failing to start it, frees the cached
> > > table and clears the pointer but leaves the size set. The next start
> > > then pairs a NULL table with a non-zero size.
> > > 
> > > The SCM backend substitutes an empty table and hides the problem. The
> > > TEE backend copies from the NULL pointer:
> > > 
> > >   remoteproc remoteproc2: powering up cdsp
> > >   pc : __pi_memcpy_generic+0x110/0x22c
> > >   lr : qcom_pas_tee_get_rsc_table+0xf4/0x25c
> > >   Call trace:
> > >    __pi_memcpy_generic+0x110/0x22c (P)
> > >    qcom_pas_get_rsc_table+0x38/0x60
> > >    qcom_pas_parse_firmware+0xa0/0x100
> > >    rproc_boot+0x2d4/0x380
> > >    state_store+0x40/0x100
> > > 
> > > Fixes: a4584bff63c8 ("remoteproc: pas: Extend parse_fw callback to fetch resources via SMC call")
> > > Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez@xxxxxxxxxxxxxxxx>
> > > ---
> > >  drivers/remoteproc/qcom_q6v5_pas.c | 11 ++++++-----
> > >  1 file changed, 6 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/drivers/remoteproc/qcom_q6v5_pas.c b/drivers/remoteproc/qcom_q6v5_pas.c
> > > index a005546c265d..e871e03ba794 100644
> > > --- a/drivers/remoteproc/qcom_q6v5_pas.c
> > > +++ b/drivers/remoteproc/qcom_q6v5_pas.c
> > > @@ -463,7 +463,7 @@ static int qcom_pas_parse_firmware(struct rproc *rproc, const struct firmware *f
> > >  	struct resource_table *table = NULL;
> > >  	size_t output_rt_size;
> > >  	void *output_rt;
> > > -	size_t table_sz;
> > > +	size_t table_sz = 0;
> > >  	int ret;
> > >  
> > >  	ret = qcom_register_dump_segments(rproc, fw);
> > > @@ -476,11 +476,12 @@ static int qcom_pas_parse_firmware(struct rproc *rproc, const struct firmware *f
> > >  		return 0;
> > >  
> > >  	ret = rproc_elf_load_rsc_table(rproc, fw);
> > > -	if (ret)
> > > +	if (ret) {
> > >  		dev_dbg(&rproc->dev, "Failed to load resource table from firmware\n");
> > > -
> > > -	table = rproc->table_ptr;
> > > -	table_sz = rproc->table_sz;
> > > +	} else {
> > > +		table = rproc->table_ptr;
> > > +		table_sz = rproc->table_sz;
> > > +	}
> > 
> > 
> > Earlier code was intentional please read the comment below.. /**...*/
> > 
> 
> AFAICS the comments say that the call might pass NULL and zero as input
> resources. And this patch does exactly that - it doesnt allow NULL and
> non-zero.
> 
> did I miss something?

No, you did not miss anything.. I just wanted to highlight that I
did not keep else statement in my initial implementation
intentionally and relied table_ptr and size will be NULL on
failure of rproc_elf_load_rsc_table()..


-- 
-Mukesh Ojha