From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755490AbdBQFL6 (ORCPT ); Fri, 17 Feb 2017 00:11:58 -0500 Received: from mail-pg0-f68.google.com ([74.125.83.68]:33424 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750880AbdBQFL4 (ORCPT ); Fri, 17 Feb 2017 00:11:56 -0500 Subject: Re: [PATCH 4/5] tpm_tis_spi: Remove limitation of transfers to MAX_SPI_FRAMESIZE bytes To: Peter Huewe , Jarkko Sakkinen References: <1487261306-2494-1-git-send-email-peter.huewe@infineon.com> <1487261306-2494-5-git-send-email-peter.huewe@infineon.com> Cc: Jason Gunthorpe , tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, peterhuewe@gmx.de, Christophe Ricard , stable@vger.kernel.org, Alexander Steffen From: Christophe Ricard Message-ID: <43990139-3687-60b6-bf1f-77593c3bcd97@gmail.com> Date: Thu, 16 Feb 2017 21:11:53 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <1487261306-2494-5-git-send-email-peter.huewe@infineon.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I am not sure i understand here, are you considering there could be burstcount > 64 with "TCG" TPM ? Or is this because of TIS vs PTP differences ? To be honest, this is a little behind me now :-) On 16/02/2017 08:08, Peter Huewe wrote: > Limiting transfers to MAX_SPI_FRAMESIZE was not expected by the upper > layers, as tpm_tis has no such limitation. Add a loop to hide that > limitation. > > Cc: > Fixes: 0edbfea537d1 ("tpm/tpm_tis_spi: Add support for spi phy") > Signed-off-by: Alexander Steffen > Signed-off-by: Peter Huewe > --- > drivers/char/tpm/tpm_tis_spi.c | 108 ++++++++++++++++++++++------------------- > 1 file changed, 57 insertions(+), 51 deletions(-) > > diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c > index 16938e2253d2..b50c5b072df3 100644 > --- a/drivers/char/tpm/tpm_tis_spi.c > +++ b/drivers/char/tpm/tpm_tis_spi.c > @@ -61,68 +61,74 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u8 len, > { > struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data); > int ret; > - struct spi_message m; > - struct spi_transfer spi_xfer = { > - .tx_buf = phy->tx_buf, > - .rx_buf = phy->rx_buf, > - .len = 4, > - .cs_change = 1, > - }; > - > - if (len > MAX_SPI_FRAMESIZE) > - return -ENOMEM; > > - phy->tx_buf[0] = direction | (len - 1); > - phy->tx_buf[1] = 0xd4; > - phy->tx_buf[2] = addr >> 8; > - phy->tx_buf[3] = addr; > + spi_bus_lock(phy->spi_device->master); > > - spi_message_init(&m); > - spi_message_add_tail(&spi_xfer, &m); > + while (len) { > + struct spi_message m; > + struct spi_transfer spi_xfer = { > + .tx_buf = phy->tx_buf, > + .rx_buf = phy->rx_buf, > + .len = 4, > + .cs_change = 1, > + }; > + u8 transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE); > + > + phy->tx_buf[0] = direction | (transfer_len - 1); > + phy->tx_buf[1] = 0xd4; > + phy->tx_buf[2] = addr >> 8; > + phy->tx_buf[3] = addr; > + > + spi_message_init(&m); > + spi_message_add_tail(&spi_xfer, &m); > + ret = spi_sync_locked(phy->spi_device, &m); > + if (ret < 0) > + goto exit; > > - spi_bus_lock(phy->spi_device->master); > - ret = spi_sync_locked(phy->spi_device, &m); > - if (ret < 0) > - goto exit; > - > - if ((phy->rx_buf[3] & 0x01) == 0) { > - // handle SPI wait states > - int i; > - > - phy->tx_buf[0] = 0; > - > - for (i = 0; i < TPM_RETRY; i++) { > - spi_xfer.len = 1; > - spi_message_init(&m); > - spi_message_add_tail(&spi_xfer, &m); > - ret = spi_sync_locked(phy->spi_device, &m); > - if (ret < 0) > + if ((phy->rx_buf[3] & 0x01) == 0) { > + // handle SPI wait states > + int i; > + > + phy->tx_buf[0] = 0; > + > + for (i = 0; i < TPM_RETRY; i++) { > + spi_xfer.len = 1; > + spi_message_init(&m); > + spi_message_add_tail(&spi_xfer, &m); > + ret = spi_sync_locked(phy->spi_device, &m); > + if (ret < 0) > + goto exit; > + if (phy->rx_buf[0] & 0x01) > + break; > + } > + > + if (i == TPM_RETRY) { > + ret = -ETIMEDOUT; > goto exit; > - if (phy->rx_buf[0] & 0x01) > - break; > + } > } > > - if (i == TPM_RETRY) { > - ret = -ETIMEDOUT; > - goto exit; > + spi_xfer.cs_change = 0; > + spi_xfer.len = transfer_len; > + > + if (direction) { > + spi_xfer.tx_buf = NULL; > + spi_xfer.rx_buf = buffer; > + } else { > + spi_xfer.tx_buf = buffer; > + spi_xfer.rx_buf = NULL; > } > - } > > - spi_xfer.cs_change = 0; > - spi_xfer.len = len; > + spi_message_init(&m); > + spi_message_add_tail(&spi_xfer, &m); > + ret = spi_sync_locked(phy->spi_device, &m); > + if (ret < 0) > + goto exit; > > - if (direction) { > - spi_xfer.tx_buf = NULL; > - spi_xfer.rx_buf = buffer; > - } else { > - spi_xfer.tx_buf = buffer; > - spi_xfer.rx_buf = NULL; > + len -= transfer_len; > + buffer += transfer_len; > } > > - spi_message_init(&m); > - spi_message_add_tail(&spi_xfer, &m); > - ret = spi_sync_locked(phy->spi_device, &m); > - > exit: > spi_bus_unlock(phy->spi_device->master); > return ret;