From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.gentoo.org (woodpecker.gentoo.org [140.211.166.183]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5F1F413777E for ; Fri, 1 May 2026 12:26:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=140.211.166.183 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777638366; cv=none; b=DaJ8R83QFk5ks25UuoqjHwH9r1Fc+AIkFxfzOgjWLlVlKrfbUGmO547oGHkxX+gB211H6WZosOKsSgQo5G7SrGwWs870ybqzIWUeAhwDD7zPdabZzBZXBSpmcoTRwve74IQP4PrIo8nUDUFV5QE3LGvoBZWq9euXw3MY7jVkynY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777638366; c=relaxed/simple; bh=LtjoycP50KAEQlhDOdjS29RKsJscFgtlcgv0aH33ceo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dGRn4kFSRhdC2YxC7tpWPTb9KU1XOawwwzQyN/YH0vVMDGOMi31XfkZzVEMfSxEUJ6T1mWT1ll+8o99QBiUNI1cu4lcNkhHaUEYFxJqqSXhTcOQIVpxNrWk3MFw+kcYk90WMXBNN8tLNs99wdKc8MJHoz0TGLJU/D3ol+1RTnZQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gentoo.org; spf=pass smtp.mailfrom=gentoo.org; arc=none smtp.client-ip=140.211.166.183 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gentoo.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gentoo.org Received: from localhost (unknown [116.232.124.22]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dlan) by smtp.gentoo.org (Postfix) with ESMTPSA id 6897D34205F; Fri, 01 May 2026 12:26:02 +0000 (UTC) Date: Fri, 1 May 2026 12:25:51 +0000 From: Yixun Lan To: Andre Przywara Cc: u-boot@lists.denx.de, linux-sunxi@lists.linux.dev, Jagan Teki , Tom Rini , Jernej Skrabec Subject: Re: [PATCH] spi: sunxi: wait for TX/RX fifo reset done Message-ID: <20260501122551-GYB3258572@gentoo.org> References: <20260421-02-spi-fifo-reset-v1-1-e2cdd4bd474d@gentoo.org> Precedence: bulk X-Mailing-List: linux-sunxi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Hi Andre, On 11:54 Thu 30 Apr , Andre Przywara wrote: > Hi, > > On 4/21/26 06:47, Yixun Lan wrote: > > Once reset SPI TX or RX fifo, the underlying hardware need to take > > some time to actually settle down, the two bits will automatically > > clear to 0, so use a poll mechanism to check status bits to make sure > > it's done correctly. > > Ah, interesting, thanks for posting this! > I looked into some manuals, and it seems like this self-clearing > property is already used in the A10, so it's fine to use unconditionally. > > > > > Signed-off-by: Yixun Lan > > Acked-by: Andre Przywara > > If you don't mind, I would pull the below paragraph into the commit > message, since it's useful to have in the git history. > No, feel free to adjust.. And thanks I'd assume you will handle all this? so no need from my side to post new version > Cheers, > Andre. > > P.S. Just curious if we need a similar fix for Linux, or are we saved by > the Linux code spending more time in setup before doing a transfer? > I've not looked into Linux/Kernel side, since this is a hardware feature, so yes, we should do something similar (to be safe) > > --- > > On Cubie A7A board which using A733 SoC, we encoutered a SPI nor flash > > timeout issue, it turns out that the SPI fifo reset take a few time to > > settle down, Add a loop to poll the status. > > > > This was the error message shows on A7A board once this issue happened. > > > > => sf probe > > ERROR: sun4i_spi: Timeout transferring data > > Failed to initialize SPI flash at 0:0 (error -2) > > --- > > drivers/spi/spi-sunxi.c | 9 ++++++--- > > 1 file changed, 6 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/spi/spi-sunxi.c b/drivers/spi/spi-sunxi.c > > index e00532a371b..cf41905c7b7 100644 > > --- a/drivers/spi/spi-sunxi.c > > +++ b/drivers/spi/spi-sunxi.c > > @@ -347,7 +347,7 @@ static int sun4i_spi_xfer(struct udevice *dev, unsigned int bitlen, > > struct sun4i_spi_priv *priv = dev_get_priv(bus); > > struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev); > > > > - u32 len = bitlen / 8; > > + u32 rst, val, len = bitlen / 8; > > u8 nbytes; > > int ret; > > > > @@ -363,8 +363,11 @@ static int sun4i_spi_xfer(struct udevice *dev, unsigned int bitlen, > > sun4i_spi_set_cs(bus, slave_plat->cs[0], true); > > > > /* Reset FIFOs */ > > - setbits_le32(SPI_REG(priv, SPI_FCR), SPI_BIT(priv, SPI_FCR_RF_RST) | > > - SPI_BIT(priv, SPI_FCR_TF_RST)); > > + rst = SPI_BIT(priv, SPI_FCR_RF_RST) | SPI_BIT(priv, SPI_FCR_TF_RST); > > + setbits_le32(SPI_REG(priv, SPI_FCR), rst); > > + ret = readl_poll_timeout(SPI_REG(priv, SPI_FCR), val, !(rst & val), 20); > > + if (ret) > > + return -EBUSY; > > > > while (len) { > > /* Setup the transfer now... */ > > > > --- > > base-commit: 88dc2788777babfd6322fa655df549a019aa1e69 > > change-id: 20260220-02-spi-fifo-reset-25e371314c3f > > > > Best regards, > -- Yixun Lan (dlan)