From: tushar.behera@linaro•org (Tushar Behera)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM: PL330: Fix driver freeze
Date: Fri, 16 Dec 2011 14:31:07 +0530 [thread overview]
Message-ID: <4EEB08D3.4050202@linaro.org> (raw)
In-Reply-To: <4EEA3300.9000402@arm.com>
On 12/15/2011 11:18 PM, Javi Merino wrote:
> On 11/12/11 19:27, Javi Merino wrote:
>> Add a req_running field to the pl330_thread to track which request (if
>> any) has been submitted to the DMA. This mechanism replaces the old
>> one in which we tried to guess the same by looking at the PC of the
>> DMA, which could prevent the driver from sending more requests if it
>> didn't guess correctly.
>>
>> Signed-off-by: Javi Merino<javi.merino@arm•com>
>> Cc: Jassi Brar<jaswinder.singh@linaro•org>
>> ---
>> arch/arm/common/pl330.c | 116 ++++++++++++++++++++---------------------------
>> 1 files changed, 49 insertions(+), 67 deletions(-)
>>
>> diff --git a/arch/arm/common/pl330.c b/arch/arm/common/pl330.c
>> index f407a6b..8d8df74 100644
>> --- a/arch/arm/common/pl330.c
>> +++ b/arch/arm/common/pl330.c
>> @@ -221,17 +221,6 @@
>> */
>> #define MCODE_BUFF_PER_REQ 256
>>
>> -/*
>> - * Mark a _pl330_req as free.
>> - * We do it by writing DMAEND as the first instruction
>> - * because no valid request is going to have DMAEND as
>> - * its first instruction to execute.
>> - */
>> -#define MARK_FREE(req) do { \
>> - _emit_END(0, (req)->mc_cpu); \
>> - (req)->mc_len = 0; \
>> - } while (0)
>> -
>> /* If the _pl330_req is available to the client */
>> #define IS_FREE(req) (*((u8 *)((req)->mc_cpu)) == CMD_DMAEND)
>>
>> @@ -301,8 +290,10 @@ struct pl330_thread {
>> struct pl330_dmac *dmac;
>> /* Only two at a time */
>> struct _pl330_req req[2];
>> - /* Index of the last submitted request */
>> + /* Index of the last enqueued request */
>> unsigned lstenq;
>> + /* Index of the last submitted request or -1 if the DMA is stopped */
>> + int req_running;
>> };
>>
>> enum pl330_dmac_state {
>> @@ -778,6 +769,22 @@ static inline void _execute_DBGINSN(struct pl330_thread *thrd,
>> writel(0, regs + DBGCMD);
>> }
>>
>> +/*
>> + * Mark a _pl330_req as free.
>> + * We do it by writing DMAEND as the first instruction
>> + * because no valid request is going to have DMAEND as
>> + * its first instruction to execute.
>> + */
>> +static void mark_free(struct pl330_thread *thrd, int idx)
>> +{
>> + struct _pl330_req *req =&thrd->req[idx];
>> +
>> + _emit_END(0, req->mc_cpu);
>> + req->mc_len = 0;
>> +
>> + thrd->req_running = -1;
>> +}
>> +
>> static inline u32 _state(struct pl330_thread *thrd)
>> {
>> void __iomem *regs = thrd->dmac->pinfo->base;
>> @@ -836,31 +843,6 @@ static inline u32 _state(struct pl330_thread *thrd)
>> }
>> }
>>
>> -/* If the request 'req' of thread 'thrd' is currently active */
>> -static inline bool _req_active(struct pl330_thread *thrd,
>> - struct _pl330_req *req)
>> -{
>> - void __iomem *regs = thrd->dmac->pinfo->base;
>> - u32 buf = req->mc_bus, pc = readl(regs + CPC(thrd->id));
>> -
>> - if (IS_FREE(req))
>> - return false;
>> -
>> - return (pc>= buf&& pc<= buf + req->mc_len) ? true : false;
>> -}
>> -
>> -/* Returns 0 if the thread is inactive, ID of active req + 1 otherwise */
>> -static inline unsigned _thrd_active(struct pl330_thread *thrd)
>> -{
>> - if (_req_active(thrd,&thrd->req[0]))
>> - return 1; /* First req active */
>> -
>> - if (_req_active(thrd,&thrd->req[1]))
>> - return 2; /* Second req active */
>> -
>> - return 0;
>> -}
>> -
>> static void _stop(struct pl330_thread *thrd)
>> {
>> void __iomem *regs = thrd->dmac->pinfo->base;
>> @@ -892,17 +874,22 @@ static bool _trigger(struct pl330_thread *thrd)
>> struct _arg_GO go;
>> unsigned ns;
>> u8 insn[6] = {0, 0, 0, 0, 0, 0};
>> + int idx;
>>
>> /* Return if already ACTIVE */
>> if (_state(thrd) != PL330_STATE_STOPPED)
>> return true;
>>
>> - if (!IS_FREE(&thrd->req[1 - thrd->lstenq]))
>> - req =&thrd->req[1 - thrd->lstenq];
>> - else if (!IS_FREE(&thrd->req[thrd->lstenq]))
>> - req =&thrd->req[thrd->lstenq];
>> - else
>> - req = NULL;
>> + idx = 1 - thrd->lstenq;
>> + if (!IS_FREE(&thrd->req[idx]))
>> + req =&thrd->req[idx];
>> + else {
>> + idx = thrd->lstenq;
>> + if (!IS_FREE(&thrd->req[idx]))
>> + req =&thrd->req[idx];
>> + else
>> + req = NULL;
>> + }
>>
>> /* Return if no request */
>> if (!req || !req->r)
>> @@ -933,6 +920,8 @@ static bool _trigger(struct pl330_thread *thrd)
>> /* Only manager can execute GO */
>> _execute_DBGINSN(thrd, insn, true);
>>
>> + thrd->req_running = idx;
>> +
>> return true;
>> }
>>
>> @@ -1382,8 +1371,8 @@ static void pl330_dotask(unsigned long data)
>>
>> thrd->req[0].r = NULL;
>> thrd->req[1].r = NULL;
>> - MARK_FREE(&thrd->req[0]);
>> - MARK_FREE(&thrd->req[1]);
>> + mark_free(thrd, 0);
>> + mark_free(thrd, 1);
>>
>> /* Clear the reset flag */
>> pl330->dmac_tbd.reset_chan&= ~(1<< i);
>> @@ -1461,14 +1450,12 @@ int pl330_update(const struct pl330_info *pi)
>>
>> thrd =&pl330->channels[id];
>>
>> - active = _thrd_active(thrd);
>> - if (!active) /* Aborted */
>> + active = thrd->req_running;
>> + if (active == -1) /* Aborted */
>> continue;
>>
>> - active -= 1;
>> -
>> rqdone =&thrd->req[active];
>> - MARK_FREE(rqdone);
>> + mark_free(thrd, active);
>>
>> /* Get going again ASAP */
>> _start(thrd);
>> @@ -1509,7 +1496,7 @@ int pl330_chan_ctrl(void *ch_id, enum pl330_chan_op op)
>> struct pl330_thread *thrd = ch_id;
>> struct pl330_dmac *pl330;
>> unsigned long flags;
>> - int ret = 0, active;
>> + int ret = 0, active = thrd->req_running;
>>
>> if (!thrd || thrd->free || thrd->dmac->state == DYING)
>> return -EINVAL;
>> @@ -1525,28 +1512,24 @@ int pl330_chan_ctrl(void *ch_id, enum pl330_chan_op op)
>>
>> thrd->req[0].r = NULL;
>> thrd->req[1].r = NULL;
>> - MARK_FREE(&thrd->req[0]);
>> - MARK_FREE(&thrd->req[1]);
>> + mark_free(thrd, 0);
>> + mark_free(thrd, 1);
>> break;
>>
>> case PL330_OP_ABORT:
>> - active = _thrd_active(thrd);
>> -
>> /* Make sure the channel is stopped */
>> _stop(thrd);
>>
>> /* ABORT is only for the active req */
>> - if (!active)
>> + if (active == -1)
>> break;
>>
>> - active--;
>> -
>> thrd->req[active].r = NULL;
>> - MARK_FREE(&thrd->req[active]);
>> + mark_free(thrd, active);
>>
>> /* Start the next */
>> case PL330_OP_START:
>> - if (!_thrd_active(thrd)&& !_start(thrd))
>> + if ((active == -1)&& !_start(thrd))
>> ret = -EIO;
>> break;
>>
>> @@ -1587,14 +1570,13 @@ int pl330_chan_status(void *ch_id, struct pl330_chanstatus *pstatus)
>> else
>> pstatus->faulting = false;
>>
>> - active = _thrd_active(thrd);
>> + active = thrd->req_running;
>>
>> - if (!active) {
>> + if (active == -1) {
>> /* Indicate that the thread is not running */
>> pstatus->top_req = NULL;
>> pstatus->wait_req = NULL;
>> } else {
>> - active--;
>> pstatus->top_req = thrd->req[active].r;
>> pstatus->wait_req = !IS_FREE(&thrd->req[1 - active])
>> ? thrd->req[1 - active].r : NULL;
>> @@ -1659,9 +1641,9 @@ void *pl330_request_channel(const struct pl330_info *pi)
>> thrd->free = false;
>> thrd->lstenq = 1;
>> thrd->req[0].r = NULL;
>> - MARK_FREE(&thrd->req[0]);
>> + mark_free(thrd, 0);
>> thrd->req[1].r = NULL;
>> - MARK_FREE(&thrd->req[1]);
>> + mark_free(thrd, 1);
>> break;
>> }
>> }
>> @@ -1767,14 +1749,14 @@ static inline void _reset_thread(struct pl330_thread *thrd)
>> thrd->req[0].mc_bus = pl330->mcode_bus
>> + (thrd->id * pi->mcbufsz);
>> thrd->req[0].r = NULL;
>> - MARK_FREE(&thrd->req[0]);
>> + mark_free(thrd, 0);
>>
>> thrd->req[1].mc_cpu = thrd->req[0].mc_cpu
>> + pi->mcbufsz / 2;
>> thrd->req[1].mc_bus = thrd->req[0].mc_bus
>> + pi->mcbufsz / 2;
>> thrd->req[1].r = NULL;
>> - MARK_FREE(&thrd->req[1]);
>> + mark_free(thrd, 1);
>> }
>>
>> static int dmac_alloc_threads(struct pl330_dmac *pl330)
>
> I've done some testing and I haven't been able to break it. Can
> somebody please test this patch with the workload that failed (audio in
> exynos I believe)?
>
Tested audio on Origen board, based on EXYNOS4210. Working fine with my
limited tests. (command line aplay).
> Thanks,
> Javi
>
> --
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--
Tushar Behera
next prev parent reply other threads:[~2011-12-16 9:01 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-19 17:11 [PATCH] ARM: pl330: Fix a race condition Javi Merino
2011-09-19 18:07 ` Jassi Brar
2011-09-20 13:36 ` Javi Merino
2011-10-05 12:57 ` Javi Merino
2011-10-06 9:10 ` [PATCH v2] " Javi Merino
2011-11-05 19:05 ` Thomas Abraham
2011-11-07 10:48 ` Javi Merino
2011-11-07 11:03 ` Thomas Abraham
2011-11-28 8:23 ` Boojin Kim
2011-11-28 16:36 ` Javi Merino
2011-11-29 3:41 ` Boojin Kim
2011-11-29 9:53 ` Javi Merino
2011-11-29 10:37 ` Jassi Brar
2011-12-07 7:52 ` Kukjin Kim
2011-12-07 10:01 ` Javi Merino
2011-12-07 20:54 ` Javi Merino
2011-12-09 11:58 ` Javi Merino
2011-12-09 13:04 ` Jassi Brar
2011-12-09 13:41 ` Javi Merino
2011-12-09 14:15 ` Jassi Brar
2011-12-09 14:52 ` Javi Merino
2011-12-09 16:50 ` Jassi Brar
2011-12-09 19:50 ` Javi Merino
2011-12-11 10:51 ` Jassi Brar
2011-12-11 15:09 ` Javi Merino
2011-12-11 17:10 ` Jassi Brar
2011-12-11 17:42 ` Javi Merino
2011-12-11 19:27 ` [PATCH] ARM: PL330: Fix driver freeze Javi Merino
2011-12-15 17:48 ` Javi Merino
2011-12-16 9:01 ` Tushar Behera [this message]
2011-12-16 6:27 ` Jassi Brar
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