From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.bootlin.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1g0p6M-0002EA-57 for linux-mtd@lists.infradead.org; Fri, 14 Sep 2018 14:29:44 +0000 Date: Fri, 14 Sep 2018 16:29:23 +0200 From: Miquel Raynal To: Masahiro Yamada Cc: linux-mtd@lists.infradead.org, Boris Brezillon , Steffen Trumtrar , linux-kernel@vger.kernel.org, Marek Vasut , Brian Norris , Richard Weinberger , David Woodhouse Subject: Re: [PATCH] mtd: rawnand: denali: fix a race condition when DMA is kicked Message-ID: <20180914162923.05c44fcc@xps13> In-Reply-To: <1536818329-11068-1-git-send-email-yamada.masahiro@socionext.com> References: <1536818329-11068-1-git-send-email-yamada.masahiro@socionext.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello, Masahiro Yamada wrote on Thu, 13 Sep 2018 14:58:49 +0900: > I thought the read-back of the DMA_ENABLE register was unnecessary > (at least it is working on my boards), then deleted it in commit > 586a2c52909d ("mtd: nand: denali: squash denali_enable_dma() helper > into caller"). Sorry, I was wrong - it caused a timing issue on > Cyclone5 SoCFPGAs. >=20 > Revive the register read-back, commenting why this is necessary. >=20 > Fixes: 586a2c52909d ("mtd: nand: denali: squash denali_enable_dma() helpe= r into caller") > Reported-by: Steffen Trumtrar > Signed-off-by: Masahiro Yamada Reviewed-by: Miquel Raynal Thanks, Miqu=C3=A8l