Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965837AbcJFIvA (ORCPT ); Thu, 6 Oct 2016 04:51:00 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48678 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965583AbcJFIu6 (ORCPT ); Thu, 6 Oct 2016 04:50:58 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Santosh Shilimkar , Arnd Bergmann , Olof Johansson , Catalin Marinas , Linus Walleij , Grygorii Strashko , Roger Quadros , Russell King Subject: [PATCH 4.4 10/93] ARM: 8617/1: dma: fix dma_max_pfn() Date: Thu, 6 Oct 2016 10:28:40 +0200 Message-Id: <20161006074731.571168480@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20161006074731.150212126@linuxfoundation.org> References: <20161006074731.150212126@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2487 Lines: 58 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Roger Quadros commit d248220f0465b818887baa9829e691fe662b2c5e upstream. 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: Greg Kroah-Hartman Cc: Santosh Shilimkar Cc: Arnd Bergmann Cc: Olof Johansson Cc: Catalin Marinas Cc: Linus Walleij Reported-by: Grygorii Strashko Signed-off-by: Roger Quadros Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/include/asm/dma-mapping.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -119,7 +119,7 @@ static inline dma_addr_t virt_to_dma(str /* 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)