linux/drivers/dma/hsu
Ferry Toth 035b73b2b3 dmaengine: hsu: disable spurious interrupt
On Intel Tangier B0 and Anniedale the interrupt line, disregarding
to have different numbers, is shared between HSU DMA and UART IPs.
Thus on such SoCs we are expecting that IRQ handler is called in
UART driver only. hsu_pci_irq was handling the spurious interrupt
from HSU DMA by returning immediately. This wastes CPU time and
since HSU DMA and HSU UART interrupt occur simultaneously they race
to be handled causing delay to the HSU UART interrupt handling.
Fix this by disabling the interrupt entirely.

Fixes: 4831e0d905 ("serial: 8250_mid: handle interrupt correctly in DMA case")
Signed-off-by: Ferry Toth <ftoth@exalondelft.nl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210112223749.97036-1-ftoth@exalondelft.nl
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-01-13 22:01:34 +05:30
..
hsu.c dmaengine updates for v5.3-rc1 2019-07-17 09:55:43 -07:00
hsu.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
pci.c dmaengine: hsu: disable spurious interrupt 2021-01-13 22:01:34 +05:30