lkml.org 
[lkml]   [2022]   [Jan]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.15 815/846] dmaengine: at_xdmac: Dont start transactions at tx_submit level
    Date
    From: Tudor Ambarus <tudor.ambarus@microchip.com>

    commit bccfb96b59179d4f96cbbd1ddff8fac6d335eae4 upstream.

    tx_submit is supposed to push the current transaction descriptor to a
    pending queue, waiting for issue_pending() to be called. issue_pending()
    must start the transfer, not tx_submit(), thus remove
    at_xdmac_start_xfer() from at_xdmac_tx_submit(). Clients of at_xdmac that
    assume that tx_submit() starts the transfer must be updated and call
    dma_async_issue_pending() if they miss to call it (one example is
    atmel_serial).

    As the at_xdmac_start_xfer() is now called only from
    at_xdmac_advance_work() when !at_xdmac_chan_is_enabled(), the
    at_xdmac_chan_is_enabled() check is no longer needed in
    at_xdmac_start_xfer(), thus remove it.

    Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
    Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
    Link: https://lore.kernel.org/r/20211215110115.191749-2-tudor.ambarus@microchip.com
    Signed-off-by: Vinod Koul <vkoul@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    drivers/dma/at_xdmac.c | 6 ------
    1 file changed, 6 deletions(-)

    --- a/drivers/dma/at_xdmac.c
    +++ b/drivers/dma/at_xdmac.c
    @@ -385,9 +385,6 @@ static void at_xdmac_start_xfer(struct a

    dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, first);

    - if (at_xdmac_chan_is_enabled(atchan))
    - return;
    -
    /* Set transfer as active to not try to start it again. */
    first->active_xfer = true;

    @@ -479,9 +476,6 @@ static dma_cookie_t at_xdmac_tx_submit(s
    dev_vdbg(chan2dev(tx->chan), "%s: atchan 0x%p, add desc 0x%p to xfers_list\n",
    __func__, atchan, desc);
    list_add_tail(&desc->xfer_node, &atchan->xfers_list);
    - if (list_is_singular(&atchan->xfers_list))
    - at_xdmac_start_xfer(atchan, desc);
    -
    spin_unlock_irqrestore(&atchan->lock, irqflags);
    return cookie;
    }

    \
     
     \ /
      Last update: 2022-01-25 01:20    [W:3.041 / U:0.396 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site