From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 51CD028DB6 for ; Mon, 16 Oct 2023 14:49:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="VX+hMS0k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF126C433C9; Mon, 16 Oct 2023 14:49:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1697467794; bh=UuP3EA/FEdeIPTYKFqoMWl/FVkGBYz+VT0KahhM0gSQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VX+hMS0kDGZS51ZgJ/LH02XEDo6XtmV1g7zdHDLSmra5rRrW1v/NdNYkpv0jEyrPw V1a8sAFxCHtxO0dmX63W89txf7+OenwcMFYvC5crLzBX9A030gpO37Q5uop2Z0PWhX nuXZ85l1IpoPqAPaUk+KSAnDf8F0sHtLW2n80CDc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Amelie Delaunay , Vinod Koul Subject: [PATCH 6.5 096/191] dmaengine: stm32-dma: fix residue in case of MDMA chaining Date: Mon, 16 Oct 2023 10:41:21 +0200 Message-ID: <20231016084017.632902383@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231016084015.400031271@linuxfoundation.org> References: <20231016084015.400031271@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Amelie Delaunay commit 67e13e89742c3b21ce177f612bf9ef32caae6047 upstream. In case of MDMA chaining, DMA is configured in Double-Buffer Mode (DBM) with two periods, but if transfer has been prepared with _prep_slave_sg(), the transfer is not marked cyclic (=!chan->desc->cyclic). However, as DBM is activated for MDMA chaining, residue computation must take into account cyclic constraints. With only two periods in MDMA chaining, and no update due to Transfer Complete interrupt masked, n_sg is always 0. If DMA current memory address (depending on SxCR.CT and SxM0AR/SxM1AR) does not correspond, it means n_sg should be increased. Then, the residue of the current period is the one read from SxNDTR and should not be overwritten with the full period length. Fixes: 723795173ce1 ("dmaengine: stm32-dma: add support to trigger STM32 MDMA") Signed-off-by: Amelie Delaunay Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20231004155024.2609531-2-amelie.delaunay@foss.st.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/stm32-dma.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -1389,11 +1389,12 @@ static size_t stm32_dma_desc_residue(str residue = stm32_dma_get_remaining_bytes(chan); - if (chan->desc->cyclic && !stm32_dma_is_current_sg(chan)) { + if ((chan->desc->cyclic || chan->trig_mdma) && !stm32_dma_is_current_sg(chan)) { n_sg++; if (n_sg == chan->desc->num_sgs) n_sg = 0; - residue = sg_req->len; + if (!chan->trig_mdma) + residue = sg_req->len; } /* @@ -1403,7 +1404,7 @@ static size_t stm32_dma_desc_residue(str * residue = remaining bytes from NDTR + remaining * periods/sg to be transferred */ - if (!chan->desc->cyclic || n_sg != 0) + if ((!chan->desc->cyclic && !chan->trig_mdma) || n_sg != 0) for (i = n_sg; i < desc->num_sgs; i++) residue += desc->sg_req[i].len;