* [bug report] i3c: master: svc: Add Silvaco I3C master driver
@ 2021-02-09 10:57 Dan Carpenter
2021-02-16 15:21 ` Miquel Raynal
0 siblings, 1 reply; 5+ messages in thread
From: Dan Carpenter @ 2021-02-09 10:57 UTC (permalink / raw)
To: miquel.raynal; +Cc: linux-i3c
Hello Miquel Raynal,
The patch dd3c52846d59: "i3c: master: svc: Add Silvaco I3C master
driver" from Jan 21, 2021, leads to the following static checker
warning:
drivers/i3c/master/svc-i3c-master.c:394 svc_i3c_master_ibi_work()
error: uninitialized symbol 'dev'.
drivers/i3c/master/svc-i3c-master.c
364 status = readl(master->regs + SVC_I3C_MSTATUS);
365 ibitype = SVC_I3C_MSTATUS_IBITYPE(status);
366 ibiaddr = SVC_I3C_MSTATUS_IBIADDR(status);
367
368 /* Handle the critical responses to IBI's */
369 switch (ibitype) {
370 case SVC_I3C_MSTATUS_IBITYPE_IBI:
371 dev = svc_i3c_master_dev_from_addr(master, ibiaddr);
372 if (!dev)
373 svc_i3c_master_nack_ibi(master);
374 else
375 svc_i3c_master_handle_ibi(master, dev);
"dev" only valid on this path.
376 break;
377 case SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN:
378 svc_i3c_master_ack_ibi(master, false);
379 break;
380 case SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST:
381 svc_i3c_master_nack_ibi(master);
382 break;
383 default:
384 break;
385 }
386
387 /*
388 * If an error happened, we probably got interrupted and the exchange
389 * timedout. In this case we just drop everything, emit a stop and wait
390 * for the slave to interrupt again.
391 */
392 if (svc_i3c_master_error(master)) {
393 if (master->ibi.tbq_slot) {
394 data = i3c_dev_get_master_data(dev);
^^^
Dereferenced here.
395 i3c_generic_ibi_recycle_slot(data->ibi_pool,
396 master->ibi.tbq_slot);
397 master->ibi.tbq_slot = NULL;
398 }
399
400 svc_i3c_master_emit_stop(master);
401
402 goto reenable_ibis;
403 }
404
405 /* Handle the non critical tasks */
regards,
dan carpenter
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [bug report] i3c: master: svc: Add Silvaco I3C master driver
2021-02-09 10:57 [bug report] i3c: master: svc: Add Silvaco I3C master driver Dan Carpenter
@ 2021-02-16 15:21 ` Miquel Raynal
2021-02-16 18:44 ` Dan Carpenter
0 siblings, 1 reply; 5+ messages in thread
From: Miquel Raynal @ 2021-02-16 15:21 UTC (permalink / raw)
To: Dan Carpenter; +Cc: linux-i3c
Hi Dan,
Thanks for the report.
Dan Carpenter <dan.carpenter@oracle.com> wrote on Tue, 9 Feb 2021
13:57:28 +0300:
> Hello Miquel Raynal,
>
> The patch dd3c52846d59: "i3c: master: svc: Add Silvaco I3C master
> driver" from Jan 21, 2021, leads to the following static checker
> warning:
>
> drivers/i3c/master/svc-i3c-master.c:394 svc_i3c_master_ibi_work()
> error: uninitialized symbol 'dev'.
>
> drivers/i3c/master/svc-i3c-master.c
> 364 status = readl(master->regs + SVC_I3C_MSTATUS);
> 365 ibitype = SVC_I3C_MSTATUS_IBITYPE(status);
> 366 ibiaddr = SVC_I3C_MSTATUS_IBIADDR(status);
> 367
> 368 /* Handle the critical responses to IBI's */
> 369 switch (ibitype) {
> 370 case SVC_I3C_MSTATUS_IBITYPE_IBI:
> 371 dev = svc_i3c_master_dev_from_addr(master, ibiaddr);
> 372 if (!dev)
> 373 svc_i3c_master_nack_ibi(master);
> 374 else
> 375 svc_i3c_master_handle_ibi(master, dev);
>
> "dev" only valid on this path.
>
> 376 break;
> 377 case SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN:
> 378 svc_i3c_master_ack_ibi(master, false);
> 379 break;
> 380 case SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST:
> 381 svc_i3c_master_nack_ibi(master);
> 382 break;
> 383 default:
> 384 break;
> 385 }
> 386
> 387 /*
> 388 * If an error happened, we probably got interrupted and the exchange
> 389 * timedout. In this case we just drop everything, emit a stop and wait
> 390 * for the slave to interrupt again.
> 391 */
> 392 if (svc_i3c_master_error(master)) {
> 393 if (master->ibi.tbq_slot) {
> 394 data = i3c_dev_get_master_data(dev);
> ^^^
> Dereferenced here.
Only svc_i3c_master_handle_ibi() populates master->ibi.tbq_slot, so dev
will only be dereferenced if svc_i3c_master_handle_ibi() was executed,
which only happens if dev is valid.
I don't think there is a risk here, however if robots really are
unhappy we might add an extra sanity level by checking dev explicitly,
but this would be purely useless on a practical point of view.
Thanks,
Miquèl
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [bug report] i3c: master: svc: Add Silvaco I3C master driver
2021-02-16 15:21 ` Miquel Raynal
@ 2021-02-16 18:44 ` Dan Carpenter
0 siblings, 0 replies; 5+ messages in thread
From: Dan Carpenter @ 2021-02-16 18:44 UTC (permalink / raw)
To: Miquel Raynal; +Cc: linux-i3c
On Tue, Feb 16, 2021 at 04:21:01PM +0100, Miquel Raynal wrote:
> Hi Dan,
>
> Thanks for the report.
>
> Dan Carpenter <dan.carpenter@oracle.com> wrote on Tue, 9 Feb 2021
> 13:57:28 +0300:
>
> > Hello Miquel Raynal,
> >
> > The patch dd3c52846d59: "i3c: master: svc: Add Silvaco I3C master
> > driver" from Jan 21, 2021, leads to the following static checker
> > warning:
> >
> > drivers/i3c/master/svc-i3c-master.c:394 svc_i3c_master_ibi_work()
> > error: uninitialized symbol 'dev'.
> >
> > drivers/i3c/master/svc-i3c-master.c
> > 364 status = readl(master->regs + SVC_I3C_MSTATUS);
> > 365 ibitype = SVC_I3C_MSTATUS_IBITYPE(status);
> > 366 ibiaddr = SVC_I3C_MSTATUS_IBIADDR(status);
> > 367
> > 368 /* Handle the critical responses to IBI's */
> > 369 switch (ibitype) {
> > 370 case SVC_I3C_MSTATUS_IBITYPE_IBI:
> > 371 dev = svc_i3c_master_dev_from_addr(master, ibiaddr);
> > 372 if (!dev)
> > 373 svc_i3c_master_nack_ibi(master);
> > 374 else
> > 375 svc_i3c_master_handle_ibi(master, dev);
> >
> > "dev" only valid on this path.
> >
> > 376 break;
> > 377 case SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN:
> > 378 svc_i3c_master_ack_ibi(master, false);
> > 379 break;
> > 380 case SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST:
> > 381 svc_i3c_master_nack_ibi(master);
> > 382 break;
> > 383 default:
> > 384 break;
> > 385 }
> > 386
> > 387 /*
> > 388 * If an error happened, we probably got interrupted and the exchange
> > 389 * timedout. In this case we just drop everything, emit a stop and wait
> > 390 * for the slave to interrupt again.
> > 391 */
> > 392 if (svc_i3c_master_error(master)) {
> > 393 if (master->ibi.tbq_slot) {
> > 394 data = i3c_dev_get_master_data(dev);
> > ^^^
> > Dereferenced here.
>
> Only svc_i3c_master_handle_ibi() populates master->ibi.tbq_slot, so dev
> will only be dereferenced if svc_i3c_master_handle_ibi() was executed,
> which only happens if dev is valid.
>
> I don't think there is a risk here, however if robots really are
> unhappy we might add an extra sanity level by checking dev explicitly,
> but this would be purely useless on a practical point of view.
Nah. I think this works. It's fine. Don't do things just to make the
robots happy.
regards,
dan carpenter
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^ permalink raw reply [flat|nested] 5+ messages in thread
* [bug report] i3c: master: svc: Add Silvaco I3C master driver
@ 2021-07-26 7:33 Dan Carpenter
2021-07-26 8:48 ` Miquel Raynal
0 siblings, 1 reply; 5+ messages in thread
From: Dan Carpenter @ 2021-07-26 7:33 UTC (permalink / raw)
To: miquel.raynal; +Cc: linux-i3c
Hello Miquel Raynal,
The patch dd3c52846d59: "i3c: master: svc: Add Silvaco I3C master
driver" from Jan 21, 2021, leads to the following static checker
warning:
drivers/i3c/master/svc-i3c-master.c:690 svc_i3c_master_do_daa_locked()
warn: sleeping in atomic context
drivers/i3c/master/svc-i3c-master.c
670 static int svc_i3c_master_do_daa_locked(struct svc_i3c_master *master,
671 u8 *addrs, unsigned int *count)
672 {
673 u64 prov_id[SVC_I3C_MAX_DEVS] = {}, nacking_prov_id = 0;
674 unsigned int dev_nb = 0, last_addr = 0;
675 u32 reg;
676 int ret, i;
677
678 while (true) {
679 /* Enter/proceed with DAA */
680 writel(SVC_I3C_MCTRL_REQUEST_PROC_DAA |
681 SVC_I3C_MCTRL_TYPE_I3C |
682 SVC_I3C_MCTRL_IBIRESP_NACK |
683 SVC_I3C_MCTRL_DIR(SVC_I3C_MCTRL_DIR_WRITE),
684 master->regs + SVC_I3C_MCTRL);
685
686 /*
687 * Either one slave will send its ID, or the assignment process
688 * is done.
689 */
--> 690 ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
691 SVC_I3C_MSTATUS_RXPEND(reg) |
692 SVC_I3C_MSTATUS_MCTRLDONE(reg),
693 1, 1000);
^
This is called with a lock held and the code is doing a 1 us sleep.
694 if (ret)
695 return ret;
696
regards,
dan carpenter
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [bug report] i3c: master: svc: Add Silvaco I3C master driver
2021-07-26 7:33 Dan Carpenter
@ 2021-07-26 8:48 ` Miquel Raynal
0 siblings, 0 replies; 5+ messages in thread
From: Miquel Raynal @ 2021-07-26 8:48 UTC (permalink / raw)
To: Dan Carpenter; +Cc: linux-i3c
Hi Dan,
Dan Carpenter <dan.carpenter@oracle.com> wrote on Mon, 26 Jul 2021
10:33:19 +0300:
> Hello Miquel Raynal,
>
> The patch dd3c52846d59: "i3c: master: svc: Add Silvaco I3C master
> driver" from Jan 21, 2021, leads to the following static checker
> warning:
>
> drivers/i3c/master/svc-i3c-master.c:690 svc_i3c_master_do_daa_locked()
> warn: sleeping in atomic context
>
> drivers/i3c/master/svc-i3c-master.c
> 670 static int svc_i3c_master_do_daa_locked(struct svc_i3c_master *master,
> 671 u8 *addrs, unsigned int *count)
> 672 {
> 673 u64 prov_id[SVC_I3C_MAX_DEVS] = {}, nacking_prov_id = 0;
> 674 unsigned int dev_nb = 0, last_addr = 0;
> 675 u32 reg;
> 676 int ret, i;
> 677
> 678 while (true) {
> 679 /* Enter/proceed with DAA */
> 680 writel(SVC_I3C_MCTRL_REQUEST_PROC_DAA |
> 681 SVC_I3C_MCTRL_TYPE_I3C |
> 682 SVC_I3C_MCTRL_IBIRESP_NACK |
> 683 SVC_I3C_MCTRL_DIR(SVC_I3C_MCTRL_DIR_WRITE),
> 684 master->regs + SVC_I3C_MCTRL);
> 685
> 686 /*
> 687 * Either one slave will send its ID, or the assignment process
> 688 * is done.
> 689 */
> --> 690 ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
> 691 SVC_I3C_MSTATUS_RXPEND(reg) |
> 692 SVC_I3C_MSTATUS_MCTRLDONE(reg),
> 693 1, 1000);
> ^
> This is called with a lock held and the code is doing a 1 us sleep.
Yes, there is a pending patch for this:
https://lore.kernel.org/patchwork/patch/1461520/
Thanks anyway for the report!
Thanks,
Miquèl
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^ permalink raw reply [flat|nested] 5+ messages in thread
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2021-02-09 10:57 [bug report] i3c: master: svc: Add Silvaco I3C master driver Dan Carpenter
2021-02-16 15:21 ` Miquel Raynal
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2021-07-26 7:33 Dan Carpenter
2021-07-26 8:48 ` Miquel Raynal
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