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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?U62A0cMKB62FRpXvKHUW76VuE+cs1oDfofxq4JtKyYeLz6wizEv6aypXURw/?= =?us-ascii?Q?4iCXXKVgSWSS75vF2WLbdba+1EpM9FFgO29SdWb3aMq0Kfd/7unRu4NkJc4t?= =?us-ascii?Q?86uS88pvZ4gaPeG4BzXsoU2ffOr/Tq8cfIk1BM2La6o8t+HZe112gewFAQ2b?= =?us-ascii?Q?527MlSbAkSOWAA964b+uIDqRCszLQHr2ETlXC7b1+theHZZyNDv9ycIsy9Hu?= =?us-ascii?Q?pZlk09GKtUfD5mXSxaQ5/OoZSiiOUD6JuBZt6ILFKR2M3bcbCZeAF6EffHeW?= =?us-ascii?Q?egici14JmyQfLOOjidMvhbAei0kIqK0QSJ2s8DEtTBJ/UDxMxcTuiczrHeT1?= =?us-ascii?Q?TvkfEr97MUq3LNBYvi5xSW8P7XpgiSJtIvdcXaaxM7a7Fg7rVXon/RG2WQi4?= =?us-ascii?Q?onVCe4OAg5j6GWS1w59nDMYGU4q2l1tW6qVBYAij8xl5UhhkMPzyrc/5sEQ+?= =?us-ascii?Q?3ILpz/o0zZOzQOSmVM1mObSbY9Skylz570m62hJ7AeTkNN0x0k9WwrZ9RRxz?= =?us-ascii?Q?sFUiJ8s7UPIvCdmeRjwnWvqfRrwZHs+WaY4KZDqAJe3TCepIBnOTh0Sniggg?= =?us-ascii?Q?v8UEOMKohB0pZYYCCy5Y6RXTnApItm85By6QTboRysirUyie4yHSlPxUDjEN?= =?us-ascii?Q?dfv9/SbXGYglW5+2hsiCMWtp3KpyOw+PKHVl8dY/NPcleAQQeSBoCfqRHLqE?= =?us-ascii?Q?vD/swqkuzLbPDABSN/HVlk4HfGqE16kvojTllJEtaJ0wgSInSy65HGMPDuI1?= =?us-ascii?Q?RqV8WC6bXvY5fpfrIXKm5/JdcauH11rIxOBuKwhOUoASAWJtCjR5IE1e2Mes?= =?us-ascii?Q?NybkGm2+2ORmgeEInSaTF9ef4fttvjcdNz8yESKCPh8TvhdFOgzEFB0LMEKb?= =?us-ascii?Q?mAOi+9w1HN03OCjsZtkme0menyNc9sj1+CG5ZXVUW26q2UpKZe2gedyuNiqc?= =?us-ascii?Q?s6VBZN3LRwj0PAyGZC3f0G8vZuTXlWThszD78/nWeYGG0nhBlxoyOdcm6oTd?= =?us-ascii?Q?F6AZs0WQYqE6jq98eheYfUGZFLviyROJkWsMEaN7Szibow0StvrCZnGXtz6E?= =?us-ascii?Q?WouHQ+NgnpTQVvkZEFlpewZHGZL+rT7rCwZy+JSlryjticvim7GCOaLxNcmA?= =?us-ascii?Q?v0BvI6seSk5pIAda5K+jQJI7VggcoHVOBuiSqi6FPDBKq91GnFl8WXDJ4+qt?= =?us-ascii?Q?luzTd+yps2IwIgHqsDVTa0ARJ3uf8GZLAkSPC/Gpmq8aHrpf6D44QaMopoBK?= =?us-ascii?Q?ms9DY4sEjmJ8FL1u6PatEhNrwgjS4t+ovjJXvB3IsUNGZjgdds0Ih2LiW5V4?= =?us-ascii?Q?j7Jwh6HBm4BcTWyBRrHjd4fGQToYpcZRTJo/wcyQoFKj2cB0C3WpEAis6yyw?= =?us-ascii?Q?5o2Xu7ObUc9rOSFD9IjabSCzjdQ0cifquLhOjBVVpN+ARuSu1yyFF/Xt6iSS?= =?us-ascii?Q?K9aQK+pbtL2PJ2DJ7mtqcPBv0nkd3LOAFjNHvmU7iv1vlpl/R5nSTn7ZlCku?= =?us-ascii?Q?NybTqqA5m9+1ogLz+EFC9u7Xu38ntaRQFAUsJeXhRADVElptpEFyOcAUUBaV?= =?us-ascii?Q?H/w8gw/Vu/7Qv68VzZxJ3K3cB922b2ZjjV51mNSfqSeQhzopC79UC40UU0nZ?= =?us-ascii?Q?ZvIJp2R3lj4A38hjCAgymMrDmcGAAESurggl0TnitrGOYzXD0RQ6gJhHFGR+?= =?us-ascii?Q?TrAmCpQyJDOqiE3POKahou+9+MVpiW6Vldg1a5isf4OmmqPLu/WwPZNJUcLw?= =?us-ascii?Q?CiDmkmsY3cEQ2EqWLCJOCtuBvLwlwfJPX2+SVsxNNTbPSWdh80Yn?= X-OriginatorOrg: oss.nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2b1e7fbe-b2b7-4649-54db-08deed8c4e8b X-MS-Exchange-CrossTenant-AuthSource: GV2PR04MB11799.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Jul 2026 16:13:20.5898 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: T701xuffPIi96zY1Gizvsmv8SW8of9ly8sS5SuM7qVWicsIAof+YYnLarSX6tNPPGGa+egMmcAvIk0DOMLrdTOG7HcWIVW14sPKr7QFcO1d2LOTJuKV0gVaTM3kT0grD X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI0PR04MB10140 On Wed, Jul 29, 2026 at 11:30:22PM +0900, Koichiro Den wrote: > Both eDMA and HDMA perform the same remote LL read-back immediately > before writing the doorbell register. > > A later patch serializes each raw doorbell write against IRQ event > capture. Keeping the read-back in the provider callback would hold > event_lock across a remote read. Move the common read-back into the > high-level dw_edma_core_ch_doorbell(), where it can run before the > serialized section. Name the provider write wrapper > dw_edma_core_do_ch_doorbell() to distinguish the raw write, and leave > dw_edma_core_ch_maybe_doorbell() to decide whether a kick is needed. > > No functional change. > > Suggested-by: Frank Li > Signed-off-by: Koichiro Den > --- Reviewed-by: Frank Li > Changes in v4: > - Make dw_edma_core_ch_doorbell() the high-level operation and rename the > provider write wrapper to dw_edma_core_do_ch_doorbell(). (Frank) > > drivers/dma/dw-edma/dw-edma-core.c | 18 ++++++++++++++++++ > drivers/dma/dw-edma/dw-edma-core.h | 2 +- > drivers/dma/dw-edma/dw-edma-v0-core.c | 16 ---------------- > drivers/dma/dw-edma/dw-hdma-v0-core.c | 16 ---------------- > 4 files changed, 19 insertions(+), 33 deletions(-) > > diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c > index bb57f2d39d1c..55849b0c862e 100644 > --- a/drivers/dma/dw-edma/dw-edma-core.c > +++ b/drivers/dma/dw-edma/dw-edma-core.c > @@ -13,6 +13,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -254,6 +255,23 @@ static void dw_edma_finish_termination(struct dw_edma_chan *chan) > chan->status = EDMA_ST_IDLE; > } > > +static void dw_edma_core_ll_sync(struct dw_edma_chan *chan) > +{ > + /* > + * Remote controller registers and LL memory may be reached through > + * different paths. Complete posted LL writes before the doorbell. > + */ > + if (!(chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL)) > + readl(chan->ll_region.vaddr.io); > +} > + > +/* Must be called with vc.lock held for an LL channel. */ > +static void dw_edma_core_ch_doorbell(struct dw_edma_chan *chan) > +{ > + dw_edma_core_ll_sync(chan); > + dw_edma_core_do_ch_doorbell(chan); > +} > + > /* Must be called with vc.lock held. */ > static void dw_edma_core_ch_maybe_doorbell(struct dw_edma_chan *chan) > { > diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h > index 6b0d475bb8b5..00ddcaacd671 100644 > --- a/drivers/dma/dw-edma/dw-edma-core.h > +++ b/drivers/dma/dw-edma/dw-edma-core.h > @@ -304,7 +304,7 @@ static inline void dw_edma_core_ll_irq_clear(struct dw_edma_chan *chan) > chan->dw->core->ll_irq_clear(chan); > } > > -static inline void dw_edma_core_ch_doorbell(struct dw_edma_chan *chan) > +static inline void dw_edma_core_do_ch_doorbell(struct dw_edma_chan *chan) > { > chan->dw->core->ch_doorbell(chan); > } > diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c > index 990cad7f0e54..e254e9f1e613 100644 > --- a/drivers/dma/dw-edma/dw-edma-v0-core.c > +++ b/drivers/dma/dw-edma/dw-edma-v0-core.c > @@ -480,20 +480,6 @@ static void dw_edma_v0_core_ch_enable(struct dw_edma_chan *chan) > upper_32_bits(chan->ll_region.paddr)); > } > > -static void dw_edma_v0_sync_ll_data(struct dw_edma_chan *chan) > -{ > - /* > - * In case of remote eDMA engine setup, the DW PCIe RP/EP internal > - * configuration registers and application memory are normally accessed > - * over different buses. Ensure LL-data reaches the memory before the > - * doorbell register is toggled by issuing the dummy-read from the remote > - * LL memory in a hope that the MRd TLP will return only after the > - * last MWr TLP is completed > - */ > - if (!(chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL)) > - readl(chan->ll_region.vaddr.io); > -} > - > static void dw_edma_v0_core_ch_config(struct dw_edma_chan *chan) > { > struct dw_edma *dw = chan->dw; > @@ -624,8 +610,6 @@ static void dw_edma_v0_core_ch_doorbell(struct dw_edma_chan *chan) > { > struct dw_edma *dw = chan->dw; > > - dw_edma_v0_sync_ll_data(chan); > - > /* Doorbell */ > SET_RW_32(dw, chan->dir, doorbell, > FIELD_PREP(EDMA_V0_DOORBELL_CH_MASK, chan->id)); > diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c > index 8edec9c95cf0..af4ab43d00ca 100644 > --- a/drivers/dma/dw-edma/dw-hdma-v0-core.c > +++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c > @@ -282,20 +282,6 @@ static void dw_hdma_v0_core_ch_enable(struct dw_edma_chan *chan) > HDMA_V0_CONSUMER_CYCLE_STAT | HDMA_V0_CONSUMER_CYCLE_BIT); > } > > -static void dw_hdma_v0_sync_ll_data(struct dw_edma_chan *chan) > -{ > - /* > - * In case of remote HDMA engine setup, the DW PCIe RP/EP internal > - * configuration registers and application memory are normally accessed > - * over different buses. Ensure LL-data reaches the memory before the > - * doorbell register is toggled by issuing the dummy-read from the remote > - * LL memory in a hope that the MRd TLP will return only after the > - * last MWr TLP is completed > - */ > - if (!(chan->dw->chip->flags & DW_EDMA_CHIP_LOCAL)) > - readl(chan->ll_region.vaddr.io); > -} > - > static void dw_hdma_v0_core_non_ll_start(struct dw_edma_chan *chan, > struct dw_edma_burst *child) > { > @@ -393,8 +379,6 @@ static void dw_hdma_v0_core_ch_doorbell(struct dw_edma_chan *chan) > { > struct dw_edma *dw = chan->dw; > > - dw_hdma_v0_sync_ll_data(chan); > - > /* Doorbell */ > SET_CH_32(dw, chan->dir, chan->id, doorbell, HDMA_V0_DOORBELL_START); > } > -- > 2.51.0 >