On 17. 04. 24, 14:45, Marek Szyprowski wrote:
I alse tried to change the "if (dma->mapped)" check in msm_start_tx() to:
1. if (dma->tx_sg.length)
2. if (dma->tx_sg.page_link & ~SG_PAGE_LINK_MASK)
but none of the above worked what is really strange and incomprehensible
for me.
Aaaah, nevermind, what about this?
Two bugs:
1) dma_map_sg() returns the number of mapped entries. Not zero!
2) And I forgot to zero tx_sg in case of error.
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -506,8 +506,8 @@ static int msm_handle_tx_dma(struct msm_port
*msm_port, unsigned int count)
kfifo_dma_out_prepare(&tport->xmit_fifo, &dma->tx_sg, 1, count);
ret = dma_map_sg(port->dev, &dma->tx_sg, 1, dma->dir);
- if (ret)
- return ret;
+ if (!ret)
+ goto zero_out;
dma->desc = dmaengine_prep_slave_sg(dma->chan, &dma->tx_sg, 1,
DMA_MEM_TO_DEV,
@@ -548,6 +548,7 @@ static int msm_handle_tx_dma(struct msm_port
*msm_port, unsigned int count)
return 0;
unmap:
dma_unmap_sg(port->dev, &dma->tx_sg, 1, dma->dir);
+zero_out:
sg_init_table(&dma->tx_sg, 1);
return ret;
}
thanks,
--
js
suse labs
