media: cx88-mpeg: clear interrupt status register before streaming video

BugLink: https://bugs.launchpad.net/bugs/1971497
[ Upstream commit 56cb61f70e547e1b0cdfe6ff5a1f1ce6242e6d96 ]

Some cx88 video cards may have transport stream status interrupts set
to 1 from cold start, causing errors like this:

  cx88xx: cx88_print_irqbits: core:irq mpeg  [0x100000] ts_err?*
  cx8802: cx8802_mpeg_irq: mpeg:general errors: 0x00100000

According to CX2388x datasheet, the interrupt status register should be
cleared before enabling IRQs to stream video.

Fix it by clearing the Transport Stream Interrupt Status register.

Signed-off-by: Daniel González Cabanelas <dgcbueu@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/media/pci/cx88/cx88-mpeg.c b/drivers/media/pci/cx88/cx88-mpeg.c
index a57c991b165b1ab84ddcd4edf79cd68dd62c8ac0..10d2971ef0624ff2b87119567d7a099565245b81 100644 (file)
--- a/drivers/media/pci/cx88/cx88-mpeg.c
+++ b/drivers/media/pci/cx88/cx88-mpeg.c
@@ -162,6 +162,9 @@ int cx8802_start_dma(struct cx8802_dev    *dev,
        cx_write(MO_TS_GPCNTRL, GP_COUNT_CONTROL_RESET);
        q->count = 0;
 
+       /* clear interrupt status register */
+       cx_write(MO_TS_INTSTAT,  0x1f1111);
+
        /* enable irqs */
        dprintk(1, "setting the interrupt mask\n");
        cx_set(MO_PCI_INTMSK, core->pci_irqmask | PCI_INT_TSINT);