From: Harvey Hunt Date: Wed, 24 Feb 2016 15:16:43 +0000 (+0000) Subject: libata: Align ata_device's id on a cacheline X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=4ee34ea3a12396f35b26d90a094c75db95080baa;p=openwrt%2Fstaging%2Fblogic.git libata: Align ata_device's id on a cacheline The id buffer in ata_device is a DMA target, but it isn't explicitly cacheline aligned. Due to this, adjacent fields can be overwritten with stale data from memory on non coherent architectures. As a result, the kernel is sometimes unable to communicate with an ATA device. Fix this by ensuring that the id buffer is cacheline aligned. This issue is similar to that fixed by Commit 84bda12af31f ("libata: align ap->sector_buf"). Signed-off-by: Harvey Hunt Cc: linux-kernel@vger.kernel.org Cc: # 2.6.18 Signed-off-by: Tejun Heo --- diff --git a/include/linux/libata.h b/include/linux/libata.h index bec2abbd7ab2..2c4ebef79d0c 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -720,7 +720,7 @@ struct ata_device { union { u16 id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */ u32 gscr[SATA_PMP_GSCR_DWORDS]; /* PMP GSCR block */ - }; + } ____cacheline_aligned; /* DEVSLP Timing Variables from Identify Device Data Log */ u8 devslp_timing[ATA_LOG_DEVSLP_SIZE];