From: Tudor Ambarus Date: Wed, 15 Dec 2021 11:01:04 +0000 (+0200) Subject: dmaengine: at_xdmac: Don't start transactions at tx_submit level X-Git-Tag: v4.4.300~7 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=436357620b85898148eb2bdc4e31efc528ce968f;p=thirdparty%2Fkernel%2Fstable.git dmaengine: at_xdmac: Don't start transactions at tx_submit level 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 Link: https://lore.kernel.org/r/20211215110115.191749-2-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 2d87018069ca0..78ba3b6e7e094 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -345,9 +345,6 @@ static void at_xdmac_start_xfer(struct at_xdmac_chan *atchan, 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; @@ -431,9 +428,6 @@ static dma_cookie_t at_xdmac_tx_submit(struct dma_async_tx_descriptor *tx) 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; }