Messages in this thread | | | Date | Fri, 19 Apr 2024 10:09:08 +0200 | Subject | Re: [PATCH 11/15] tty: msm_serial: use dmaengine_prep_slave_sg() | From | Jiri Slaby <> |
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On 19. 04. 24, 10:00, Marek Szyprowski wrote: > On 19.04.2024 09:53, Jiri Slaby wrote: >> On 19. 04. 24, 9:43, Jiri Slaby wrote: >>> 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) >> >> Still wrong, ret = -EIO missing in here. > > "if (ret <= 0)" seems to be better here.
It returns unsigned, so I have a better patch. Will send in a second.
> Indeed this fixed the issue. I checked the code many times, but I missed > this dma_map_sg() return value issue.
Perfect!
> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Could you test that one too :)?
thanks, -- js suse labs
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