Roger Quadros d248220f04 ARM: 8617/1: dma: fix dma_max_pfn() ... Since commit 6ce0d20016 ("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: 6ce0d20016 ("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>		2016-09-29 16:57:44 +01:00
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asm	ARM: 8617/1: dma: fix dma_max_pfn()	2016-09-29 16:57:44 +01:00
debug	ARM: clps711x: Reduce static map size	2016-07-06 17:38:52 +02:00
uapi/asm	kvm arm/arm64: Remove trailing whitespace from headers	2016-07-12 15:20:36 -03:00