From: Daniel Glöckner <dg@xxxxxxxxx> On tx channel abort a cppi interrupt is generated for a short time by setting the lowest bit of the TCPPICOMPPTR register. It is then reset immediately by clearing the bit. When the interrupt handler is run, it does not detect an interrupt in the TCPPIMSKSR or RCPPIMSKSR registers and thus exits early without writing the TCPPIEOIR register. It appears that this inhibits further cppi interrupts until the handler is called by chance, f.ex. from davinci_interrupt(). By moving the unmasking of the interrupt below the writes to TCPPICOMPPTR, no interrupt is generated and no write to TCPPIEOIR is necessary. Signed-off-by: Daniel Glöckner <dg@xxxxxxxxx> Signed-off-by: Ajay Kumar Gupta <ajay.gupta@xxxxxx> --- drivers/usb/musb/cppi_dma.c | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/usb/musb/cppi_dma.c b/drivers/usb/musb/cppi_dma.c index c3577bb..ef2332a 100644 --- a/drivers/usb/musb/cppi_dma.c +++ b/drivers/usb/musb/cppi_dma.c @@ -1442,11 +1442,6 @@ static int cppi_channel_abort(struct dma_channel *channel) musb_writew(regs, MUSB_TXCSR, value); musb_writew(regs, MUSB_TXCSR, value); - /* re-enable interrupt */ - if (enabled) - musb_writel(tibase, DAVINCI_TXCPPI_INTENAB_REG, - (1 << cppi_ch->index)); - /* While we scrub the TX state RAM, ensure that we clean * up any interrupt that's currently asserted: * 1. Write to completion Ptr value 0x1(bit 0 set) @@ -1459,6 +1454,11 @@ static int cppi_channel_abort(struct dma_channel *channel) cppi_reset_tx(tx_ram, 1); musb_writel(&tx_ram->tx_complete, 0, 0); + /* re-enable interrupt */ + if (enabled) + musb_writel(tibase, DAVINCI_TXCPPI_INTENAB_REG, + (1 << cppi_ch->index)); + cppi_dump_tx(5, cppi_ch, " (done teardown)"); /* REVISIT tx side _should_ clean up the same way -- 1.6.2.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
