On Mon, Nov 1, 2021 at 6:57 AM Ricardo Martinez <ricardo.martinez@xxxxxxxxxxxxxxx> wrote: > Cross Layer DMA (CLDMA) Hardware interface (HIF) enables the control > path of Host-Modem data transfers. CLDMA HIF layer provides a common > interface to the Port Layer. > > CLDMA manages 8 independent RX/TX physical channels with data flow > control in HW queues. CLDMA uses ring buffers of General Packet > Descriptors (GPD) for TX/RX. GPDs can represent multiple or single > data buffers (DB). > > CLDMA HIF initializes GPD rings, registers ISR handlers for CLDMA > interrupts, and initializes CLDMA HW registers. > > CLDMA TX flow: > 1. Port Layer write > 2. Get DB address > 3. Configure GPD > 4. Triggering processing via HW register write > > CLDMA RX flow: > 1. CLDMA HW sends a RX "done" to host > 2. Driver starts thread to safely read GPD > 3. DB is sent to Port layer > 4. Create a new buffer for GPD ring [skipped] > diff --git a/drivers/net/wwan/t7xx/t7xx_hif_cldma.c b/drivers/net/wwan/t7xx/t7xx_hif_cldma.c > ... > +static struct cldma_ctrl *cldma_md_ctrl[CLDMA_NUM]; Place this pointers array to a private _device_ state structure. Otherwise, with these global pointers, the driver will break as soon as a second modem is connected to the host. Also all corresponding functions should be reworked to be able to accept a modem state container pointer. > +static DEFINE_MUTEX(ctl_cfg_mutex); /* protects CLDMA late init config */ Place this mutex to a private device state structure as well to avoid useless inter-device locking and possible deadlocks. > +static enum cldma_queue_type rxq_type[CLDMA_RXQ_NUM]; > +static enum cldma_queue_type txq_type[CLDMA_TXQ_NUM]; > +static int rxq_buff_size[CLDMA_RXQ_NUM]; > +static int rxq_buff_num[CLDMA_RXQ_NUM]; > +static int txq_buff_num[CLDMA_TXQ_NUM]; If these arrays could be shared between modem instances (i.e. if this is a some kind of static configuration) then initialize them statically or in the module_init(). Otherwise, if these arrays are part of the runtime state, then place them in a device state container. -- Sergey
