From 7e8ba228d9f43a4e4b3ed0e6aa3399e8f30d7bc1 Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Thu, 11 Aug 2011 15:25:48 +0000 Subject: [PATCH] mmc: atmel-mci: fix a potential issue about pending PDC interrupts This patch fixes a potential issue about PDC interrupts. For example we have a ENDRX pending interrupt and a RXBUFF pending interrupt. We have received the RXBUFF interrupt but the transfer is not finished (so we didn't have time to give a new buffer to the PDC controller). Then we will compute ENDRX interrupt and we will give a new buffer to the PDC controller, just after we will compute the RXBUFF interrupt and give one or two new buffers to the PDC controller but we are not sure that the first buffer given has been filled. So in this situation we may have "lost" one sg buffer. It's the same for transmission. Signed-off-by: Ludovic Desroches Signed-off-by: Nicolas Ferre Signed-off-by: Chris Ball --- drivers/mmc/host/atmel-mci.c | 50 +++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 24 deletions(-) diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 96004c9fe3a5..a7ee50271465 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -1729,17 +1729,9 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) tasklet_schedule(&host->tasklet); } - if (pending & ATMCI_ENDTX) { - atmci_writel(host, ATMCI_IDR, ATMCI_ENDTX); - if (host->data_size) { - atmci_pdc_set_single_buf(host, - XFER_TRANSMIT, PDC_SECOND_BUF); - atmci_writel(host, ATMCI_IER, ATMCI_ENDTX); - } - } - if (pending & ATMCI_TXBUFE) { atmci_writel(host, ATMCI_IDR, ATMCI_TXBUFE); + atmci_writel(host, ATMCI_IDR, ATMCI_ENDTX); /* * We can receive this interruption before having configured * the second pdc buffer, so we need to reconfigure first and @@ -1747,13 +1739,37 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) */ if (host->data_size) { atmci_pdc_set_both_buf(host, XFER_TRANSMIT); + atmci_writel(host, ATMCI_IER, ATMCI_ENDTX); atmci_writel(host, ATMCI_IER, ATMCI_TXBUFE); } else { atmci_pdc_complete(host); } + } else if (pending & ATMCI_ENDTX) { + atmci_writel(host, ATMCI_IDR, ATMCI_ENDTX); + + if (host->data_size) { + atmci_pdc_set_single_buf(host, + XFER_TRANSMIT, PDC_SECOND_BUF); + atmci_writel(host, ATMCI_IER, ATMCI_ENDTX); + } } - if (pending & ATMCI_ENDRX) { + if (pending & ATMCI_RXBUFF) { + atmci_writel(host, ATMCI_IDR, ATMCI_RXBUFF); + atmci_writel(host, ATMCI_IDR, ATMCI_ENDRX); + /* + * We can receive this interruption before having configured + * the second pdc buffer, so we need to reconfigure first and + * second buffers again + */ + if (host->data_size) { + atmci_pdc_set_both_buf(host, XFER_RECEIVE); + atmci_writel(host, ATMCI_IER, ATMCI_ENDRX); + atmci_writel(host, ATMCI_IER, ATMCI_RXBUFF); + } else { + atmci_pdc_complete(host); + } + } else if (pending & ATMCI_ENDRX) { atmci_writel(host, ATMCI_IDR, ATMCI_ENDRX); if (host->data_size) { @@ -1763,20 +1779,6 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) } } - if (pending & ATMCI_RXBUFF) { - atmci_writel(host, ATMCI_IDR, ATMCI_RXBUFF); - /* - * We can receive this interruption before having configured - * the second pdc buffer, so we need to reconfigure first and - * second buffers again - */ - if (host->data_size) { - atmci_pdc_set_both_buf(host, XFER_RECEIVE); - atmci_writel(host, ATMCI_IER, ATMCI_RXBUFF); - } else { - atmci_pdc_complete(host); - } - } if (pending & ATMCI_NOTBUSY) { atmci_writel(host, ATMCI_IDR,