On 31.01.2015 00:25, Greg KH wrote: >> Under pressure, the imx.c device driver may transfer the same data multiple >> times. >> >> Reason: >> Function imx_dma_tx checks for an active DMA transfer by calling >> dmaengine_tx_status. The return value may indicate that no transfer is >> running while the dma_tx_callback function is still being executed. In >> this case the xmit->tail pointer may not be updated to the correct value >> when imx_dma_tx initiates a new DMA transfer, which will result in a DMA >> transfer with the same base address as the previous one. >> >> Patch: >> Use existing dma_is_txing variable to guard DMA transfer initiation instead >> of dmaengine_tx_status. Clear dma_is_txing at the end of the DMA callback >> function therefore extending the critical section where the port lock is >> held. Critical section extension is in line with the callback function >> of other drivers, e.g. serial-tegra.c (tegra_uart_tx_dma_complete). >> >> >> Signed-off-by: Michael Doswald <michael.doswald@xxxxxxx> >> --- >> drivers/tty/serial/imx.c | 11 ++++------- >> 1 file changed, 4 insertions(+), 7 deletions(-) > > Fails to apply to my tree :( > Hi, I'm sorry, it seems I made the mistake to create the patch against 3.19-rc3 instead of rc4. I just saw that the rc4 tree already contains a patch which fixes the exact same problem (commit 42f752b3fbcfee9c27e4f6f6216e60e130ba98c8 by Dirk Behme). Thank you for notifying me. Regards, Michael -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
