diff options
| -rw-r--r-- | drivers/dma/ste_dma40.c | 20 | ||||
| -rw-r--r-- | include/linux/platform_data/dma-ste-dma40.h | 8 |
2 files changed, 27 insertions, 1 deletions
diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c index e317debdbe5..2ecefb7113b 100644 --- a/drivers/dma/ste_dma40.c +++ b/drivers/dma/ste_dma40.c @@ -355,6 +355,7 @@ struct d40_lcla_pool { * @allocated_dst: Same as for src but is dst. * allocated_dst and allocated_src uses the D40_ALLOC* defines as well as * event line number. + * @use_soft_lli: To mark if the linked lists of channel are managed by SW. */ struct d40_phy_res { spinlock_t lock; @@ -362,6 +363,7 @@ struct d40_phy_res { int num; u32 allocated_src; u32 allocated_dst; + bool use_soft_lli; }; struct d40_base; @@ -783,7 +785,16 @@ static void d40_log_lli_to_lcxa(struct d40_chan *chan, struct d40_desc *desc) * can't link back to the one in LCPA space */ if (linkback || (lli_len - lli_current > 1)) { - curr_lcla = d40_lcla_alloc_one(chan, desc); + /* + * If the channel is expected to use only soft_lli don't + * allocate a lcla. This is to avoid a HW issue that exists + * in some controller during a peripheral to memory transfer + * that uses linked lists. + */ + if (!(chan->phy_chan->use_soft_lli && + chan->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM)) + curr_lcla = d40_lcla_alloc_one(chan, desc); + first_lcla = curr_lcla; } @@ -3063,6 +3074,13 @@ static int __init d40_phy_res_init(struct d40_base *base) num_phy_chans_avail--; } + /* Mark soft_lli channels */ + for (i = 0; i < base->plat_data->num_of_soft_lli_chans; i++) { + int chan = base->plat_data->soft_lli_chans[i]; + + base->phy_res[chan].use_soft_lli = true; + } + dev_info(base->dev, "%d of %d physical DMA channels available\n", num_phy_chans_avail, base->num_phy_chans); diff --git a/include/linux/platform_data/dma-ste-dma40.h b/include/linux/platform_data/dma-ste-dma40.h index b99024ba94e..4b781014b0a 100644 --- a/include/linux/platform_data/dma-ste-dma40.h +++ b/include/linux/platform_data/dma-ste-dma40.h @@ -147,6 +147,12 @@ struct stedma40_chan_cfg { * @memcpy_conf_log: default configuration of logical channel memcpy * @disabled_channels: A vector, ending with -1, that marks physical channels * that are for different reasons not available for the driver. + * @soft_lli_chans: A vector, that marks physical channels will use LLI by SW + * which avoids HW bug that exists in some versions of the controller. + * SoftLLI introduces relink overhead that could impact performace for + * certain use cases. + * @num_of_soft_lli_chans: The number of channels that needs to be configured + * to use SoftLLI. * @use_esram_lcla: flag for mapping the lcla into esram region * @num_of_phy_chans: The number of physical channels implemented in HW. * 0 means reading the number of channels from DMA HW but this is only valid @@ -161,6 +167,8 @@ struct stedma40_platform_data { struct stedma40_chan_cfg *memcpy_conf_phy; struct stedma40_chan_cfg *memcpy_conf_log; int disabled_channels[STEDMA40_MAX_PHYS]; + int *soft_lli_chans; + int num_of_soft_lli_chans; bool use_esram_lcla; int num_of_phy_chans; }; |