From: Sven Schnelle <svens@stackframe.org>
Date: Tue, 24 Sep 2019 17:01:31 +0200
Subject: [PATCH] parisc: Remove 32-bit DMA enforcement from sba_iommu
Git-commit: c32c47aa364096124c9c69c1a44918433832562b
Patch-Mainline: v5.4-rc4
References: bsc#1175995,jsc#SLE-15608
This breaks booting from sata_sil24 with the recent DMA change.
According to James Bottomley this was in to improve performance by
kicking the device into 32 bit descriptors, which are usually more
efficient, especially with older dual descriptor format cards like we
have on parisc systems.
Remove it for now to make DMA working again.
Fixes: dcc02c19cc06 ("sata_sil24: use dma_set_mask_and_coherent")
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/parisc/sba_iommu.c | 8 --------
1 file changed, 8 deletions(-)
diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index ed50502cc65a..de8e4e347249 100644
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -678,14 +678,6 @@ static int sba_dma_supported( struct device *dev, u64 mask)
return(0);
}
- /* Documentation/DMA-API-HOWTO.txt tells drivers to try 64-bit
- * first, then fall back to 32-bit if that fails.
- * We are just "encouraging" 32-bit DMA masks here since we can
- * never allow IOMMU bypass unless we add special support for ZX1.
- */
- if (mask > ~0U)
- return 0;
-
ioc = GET_IOC(dev);
if (!ioc)
return 0;
--
2.16.4