From nobody Sat Oct 25 13:21:43 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=linaro.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1521476855226810.0370838761115; Mon, 19 Mar 2018 09:27:35 -0700 (PDT) Received: from localhost ([::1]:42910 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1exxdG-0005Ip-5g for importer@patchew.org; Mon, 19 Mar 2018 12:27:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46143) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1exxbJ-000433-C4 for qemu-devel@nongnu.org; Mon, 19 Mar 2018 12:25:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1exxbI-0007LP-2x for qemu-devel@nongnu.org; Mon, 19 Mar 2018 12:25:33 -0400 Received: from orth.archaic.org.uk ([2001:8b0:1d0::2]:40436) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1exxbE-0007Ez-Er; Mon, 19 Mar 2018 12:25:28 -0400 Received: from pm215 by orth.archaic.org.uk with local (Exim 4.89) (envelope-from ) id 1exxS3-0002tj-Lr; Mon, 19 Mar 2018 16:15:59 +0000 From: Peter Maydell To: qemu-arm@nongnu.org, qemu-devel@nongnu.org Date: Mon, 19 Mar 2018 16:15:56 +0000 Message-Id: <20180319161556.16446-3-peter.maydell@linaro.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180319161556.16446-1-peter.maydell@linaro.org> References: <20180319161556.16446-1-peter.maydell@linaro.org> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2001:8b0:1d0::2 Subject: [Qemu-devel] [PATCH for-2.12 2/2] hw/sd/bcm2835_sdhost: Don't raise spurious interrupts X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Pekka Enberg , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Gerd Hoffmann , Andrew Baumann , patches@linaro.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The Linux bcm2835_sdhost driver doesn't work on QEMU, because our model raises spurious data interrupts. Our function bcm2835_sdhost_fifo_run() will flag an interrupt any time it is called with s->datacnt =3D=3D 0, even if the host hasn't actually issued a data read or write command yet. This means that the driver gets a spurious data interrupt as soon as it enables IRQs and then does something else that causes us to call the fifo_run routine, like writing to SDHCFG, and before it does the write to SDCMD to issue the read. The driver's IRQ handler then spins forever complaining that there's no data and the SD controller isn't in a state where there's going to be any data: [ 41.040738] sdhost-bcm2835 3f202000.mmc: fsm 1, hsts 00000000 [ 41.042059] sdhost-bcm2835 3f202000.mmc: fsm 1, hsts 00000000 (continues forever). Move the interrupt flag setting to more plausible places: * for BUSY, raise this as soon as a BUSYWAIT command has executed * for DATA, raise this when the FIFO has any space free (for a write) or any data in it (for a read) * for BLOCK, raise this when the data count is 0 and we've actually done some reading or writing This is pure guesswork since the documentation for this hardware is not public, but it is sufficient to get the Linux bcm2835_sdhost driver to work. Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- hw/sd/bcm2835_sdhost.c | 43 +++++++++++++++++++++++-------------------- 1 file changed, 23 insertions(+), 20 deletions(-) diff --git a/hw/sd/bcm2835_sdhost.c b/hw/sd/bcm2835_sdhost.c index 79f3c5ceeb..0fd0853fa3 100644 --- a/hw/sd/bcm2835_sdhost.c +++ b/hw/sd/bcm2835_sdhost.c @@ -137,6 +137,9 @@ static void bcm2835_sdhost_send_command(BCM2835SDHostSt= ate *s) } #undef RWORD } + if ((s->cmd & SDCMD_BUSYWAIT) && (s->config & SDHCFG_BUSY_IRPT_EN)) { + s->status |=3D SDHSTS_BUSY_IRPT; + } return; =20 error: @@ -187,18 +190,27 @@ static void bcm2835_sdhost_fifo_run(BCM2835SDHostStat= e *s) n++; if (n =3D=3D 4) { bcm2835_sdhost_fifo_push(s, value); + s->status |=3D SDHSTS_DATA_FLAG; + if (s->config & SDHCFG_DATA_IRPT_EN) { + s->status |=3D SDHSTS_SDIO_IRPT; + } n =3D 0; value =3D 0; } } if (n !=3D 0) { bcm2835_sdhost_fifo_push(s, value); + s->status |=3D SDHSTS_DATA_FLAG; } } else { /* write */ n =3D 0; while (s->datacnt > 0 && (s->fifo_len > 0 || n > 0)) { if (n =3D=3D 0) { value =3D bcm2835_sdhost_fifo_pop(s); + s->status |=3D SDHSTS_DATA_FLAG; + if (s->config & SDHCFG_DATA_IRPT_EN) { + s->status |=3D SDHSTS_SDIO_IRPT; + } n =3D 4; } n--; @@ -207,28 +219,19 @@ static void bcm2835_sdhost_fifo_run(BCM2835SDHostStat= e *s) value >>=3D 8; } } + if (s->datacnt =3D=3D 0) { + s->edm &=3D ~0xf; + s->edm |=3D SDEDM_FSM_DATAMODE; + trace_bcm2835_sdhost_edm_change("datacnt 0", s->edm); + + if ((s->cmd & SDCMD_WRITE_CMD) && + (s->config & SDHCFG_BLOCK_IRPT_EN)) { + s->status |=3D SDHSTS_BLOCK_IRPT; + } + } } - if (s->datacnt =3D=3D 0) { - s->status |=3D SDHSTS_DATA_FLAG; =20 - s->edm &=3D ~0xf; - s->edm |=3D SDEDM_FSM_DATAMODE; - trace_bcm2835_sdhost_edm_change("datacnt 0", s->edm); - - if (s->config & SDHCFG_DATA_IRPT_EN) { - s->status |=3D SDHSTS_SDIO_IRPT; - } - - if ((s->cmd & SDCMD_BUSYWAIT) && (s->config & SDHCFG_BUSY_IRPT_EN)= ) { - s->status |=3D SDHSTS_BUSY_IRPT; - } - - if ((s->cmd & SDCMD_WRITE_CMD) && (s->config & SDHCFG_BLOCK_IRPT_E= N)) { - s->status |=3D SDHSTS_BLOCK_IRPT; - } - - bcm2835_sdhost_update_irq(s); - } + bcm2835_sdhost_update_irq(s); =20 s->edm &=3D ~(0x1f << 4); s->edm |=3D ((s->fifo_len & 0x1f) << 4); --=20 2.16.2