[PATCH 5.4 15/24] media: cx23885: add more quirks for reset DMA on some AMD IOMMU

From: gregkh
Date: Wed Mar 10 2021 - 08:29:02 EST


From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

From: Daniel Lee Kruse <daniel.lee.kruse@xxxxxxxxxxxxxx>

[ Upstream commit dbf0b3a7b719eb3f72cb53c2ce7d34a012a9c261 ]

On AMD Family 15h (Models 30h-3fh), I/O Memory Management Unit
RiSC engine sometimes stalls, requiring a reset.

As result, MythTV and w-scan won't scan channels on the AMD Kaveri
APU with the Hauppauge QuadHD TV tuner card.

For the solution I added the Input/Output Memory Management Unit's PCI
Identity of 0x1423 to the broken_dev_id[] array, which is used by
a quirks logic meant to fix similar problems with other AMD
chipsets.

Signed-off-by: Daniel Lee Kruse <daniel.lee.kruse@xxxxxxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/media/pci/cx23885/cx23885-core.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/media/pci/cx23885/cx23885-core.c b/drivers/media/pci/cx23885/cx23885-core.c
index 7e0b0b7cc2a3..ead0acb7807c 100644
--- a/drivers/media/pci/cx23885/cx23885-core.c
+++ b/drivers/media/pci/cx23885/cx23885-core.c
@@ -2074,6 +2074,10 @@ static struct {
* 0x1451 is PCI ID for the IOMMU found on Ryzen
*/
{ PCI_VENDOR_ID_AMD, 0x1451 },
+ /* According to sudo lspci -nn,
+ * 0x1423 is the PCI ID for the IOMMU found on Kaveri
+ */
+ { PCI_VENDOR_ID_AMD, 0x1423 },
};

static bool cx23885_does_need_dma_reset(void)
--
2.30.1