diff options
| author | Roger Quadros <rogerq@ti.com> | 2016-09-29 08:32:55 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2016-09-29 16:57:44 +0100 |
| commit | d248220f0465b818887baa9829e691fe662b2c5e (patch) | |
| tree | a7eba33d46ee26de6a5d6738b0ba4c870d0f3f04 | |
| parent | ba6dea4f7cedb4b1c17e36f4087675d817c2e24b (diff) | |
| download | linux-d248220f0465b818887baa9829e691fe662b2c5e.tar.bz2 | |
ARM: 8617/1: dma: fix dma_max_pfn()
Since commit 6ce0d2001692 ("ARM: dma: Use dma_pfn_offset for dma address translation"),
dma_to_pfn() already returns the PFN with the physical memory start offset
so we don't need to add it again.
This fixes USB mass storage lock-up problem on systems that can't do DMA
over the entire physical memory range (e.g.) Keystone 2 systems with 4GB RAM
can only do DMA over the first 2GB. [K2E-EVM].
What happens there is that without this patch SCSI layer sets a wrong
bounce buffer limit in scsi_calculate_bounce_limit() for the USB mass
storage device. dma_max_pfn() evaluates to 0x8fffff and bounce_limit
is set to 0x8fffff000 whereas maximum DMA'ble physical memory on Keystone 2
is 0x87fffffff. This results in non DMA'ble pages being given to the
USB controller and hence the lock-up.
NOTE: in the above case, USB-SCSI-device's dma_pfn_offset was showing as 0.
This should have really been 0x780000 as on K2e, LOWMEM_START is 0x80000000
and HIGHMEM_START is 0x800000000. DMA zone is 2GB so dma_max_pfn should be
0x87ffff. The incorrect dma_pfn_offset for the USB storage device is because
USB devices are not correctly inheriting the dma_pfn_offset from the
USB host controller. This will be fixed by a separate patch.
Fixes: 6ce0d2001692 ("ARM: dma: Use dma_pfn_offset for dma address translation")
Cc: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reported-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index d009f7911ffc..bf02dbd9ccda 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -111,7 +111,7 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) /* The ARM override for dma_max_pfn() */ static inline unsigned long dma_max_pfn(struct device *dev) { - return PHYS_PFN_OFFSET + dma_to_pfn(dev, *dev->dma_mask); + return dma_to_pfn(dev, *dev->dma_mask); } #define dma_max_pfn(dev) dma_max_pfn(dev) |