From: Sinan Kaya Date: Fri, 7 Apr 2017 19:06:18 +0000 (-0400) Subject: scsi: mpt3sas: remove redundant wmb X-Git-Tag: v4.1.12-102.0.20170601_1400~227 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=e6312dd3d201562b8255b12c9f266e0307d62bc8;p=users%2Fjedix%2Flinux-maple.git scsi: mpt3sas: remove redundant wmb Orabug: 26096353 Due to relaxed ordering requirements on multiple architectures, drivers are required to use wmb/rmb/mb combinations when they need to guarantee observability between the memory and the HW. The mpt3sas driver is already using wmb() for this purpose. However, it issues a writel following wmb(). writel() function on arm/arm64 arhictectures have an embedded wmb() call inside. This results in unnecessary performance loss and code duplication. writel already guarantees ordering for both cpu and bus. we don't need additional wmb() Signed-off-by: Sinan Kaya Acked-by: Sreekanth Reddy Reviewed-by: Brian King Signed-off-by: Martin K. Petersen (cherry picked from commit b1391a5bf83a593bbe92d1f9bddaf563be5c7c9d) Signed-off-by: Shan Hai --- diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c index 7c729ff4b7263..1239cc3caadc9 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_base.c +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c @@ -1025,7 +1025,6 @@ _base_interrupt(int irq, void *bus_id) 0 : ioc->reply_free_host_index + 1; ioc->reply_free[ioc->reply_free_host_index] = cpu_to_le32(reply); - wmb(); writel(ioc->reply_free_host_index, &ioc->chip->ReplyFreeHostIndex); } @@ -1074,7 +1073,6 @@ _base_interrupt(int irq, void *bus_id) return IRQ_NONE; } - wmb(); if (ioc->is_warpdrive) { writel(reply_q->reply_post_host_index, ioc->reply_post_host_index[msix_index]);