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authorMark A. Greer <mgreer@animalcreek.com>2014-09-02 22:12:30 (GMT)
committerSamuel Ortiz <sameo@linux.intel.com>2014-09-07 21:13:44 (GMT)
commitbece3c544fee62ba7750f70b214d612fd02dcc8f (patch)
tree6ac60b17bcda0b575d3cd39d7625882fb6d1e138 /drivers/nfc/trf7970a.c
parent0e840ed59ba79670b66bba8c1d50b6f67e72d3fb (diff)
downloadlinux-bece3c544fee62ba7750f70b214d612fd02dcc8f.tar.xz
NFC: trf7970a: Handle low-watermark IRQ when transmitting
Commit 4dd836e46c3d ("NFC: trf7970a: Reset FIFO when 'End of TX' Interrupt Occurs") fixes the issue that it was meant to fix but adds the unfortunate side effect of causing the driver to report an error when the TX low-watermark level is passed during transmits. This can be fixed by checking whether the IRQ status indicates that the low-watermark has been passed when transmitting. If it has been passed and the FIFO is empty, then its safe to reset the FIFO. Otherwise, silently continue since another TX interrupt will be generated and the FIFO will be reset then. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Diffstat (limited to 'drivers/nfc/trf7970a.c')
-rw-r--r--drivers/nfc/trf7970a.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index e9e961f..6d2b06d 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -667,7 +667,7 @@ static irqreturn_t trf7970a_irq(int irq, void *dev_id)
{
struct trf7970a *trf = dev_id;
int ret;
- u8 status;
+ u8 status, fifo_bytes;
mutex_lock(&trf->lock);
@@ -720,6 +720,16 @@ static irqreturn_t trf7970a_irq(int irq, void *dev_id)
trf->ignore_timeout =
!cancel_delayed_work(&trf->timeout_work);
trf7970a_drain_fifo(trf, status);
+ } else if (status & TRF7970A_IRQ_STATUS_FIFO) {
+ ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
+ &fifo_bytes);
+
+ fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
+
+ if (ret)
+ trf7970a_send_err_upstream(trf, ret);
+ else if (!fifo_bytes)
+ trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
} else if (status == TRF7970A_IRQ_STATUS_TX) {
trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
} else {