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path: root/drivers/usb/host/ehci-fsl.h
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/* Copyright (C) 2005-2010,2012 Freescale Semiconductor, Inc.
 * Copyright (c) 2005 MontaVista Software
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the  GNU General Public License along
 * with this program; if not, write  to the Free Software Foundation, Inc.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#ifndef _EHCI_FSL_H
#define _EHCI_FSL_H

/* offsets for the non-ehci registers in the FSL SOC USB controller */
#define FSL_SOC_USB_SBUSCFG	0x90
#define SBUSCFG_INCR8		0x02	/* INCR8, specified */
#define FSL_SOC_USB_ULPIVP	0x170
#define FSL_SOC_USB_PORTSC1	0x184
#define PORT_PTS_MSK		(3<<30)
#define PORT_PTS_UTMI		(0<<30)
#define PORT_PTS_ULPI		(2<<30)
#define	PORT_PTS_SERIAL		(3<<30)
#define PORT_PTS_PTW		(1<<28)
#define FSL_SOC_USB_PORTSC2	0x188
#define FSL_SOC_USB_USBMODE	0x1a8
#define USBMODE_CM_MASK		(3 << 0)	/* controller mode mask */
#define USBMODE_CM_HOST		(3 << 0)	/* controller mode: host */
#define USBMODE_ES		(1 << 2)	/* (Big) Endian Select */

#define FSL_SOC_USB_USBGENCTRL	0x200
#define USBGENCTRL_PPP		(1 << 3)
#define USBGENCTRL_PFP		(1 << 2)
#define FSL_SOC_USB_ISIPHYCTRL	0x204
#define ISIPHYCTRL_PXE		(1)
#define ISIPHYCTRL_PHYE		(1 << 4)

#define FSL_SOC_USB_SNOOP1	0x400	/* NOTE: big-endian */
#define FSL_SOC_USB_SNOOP2	0x404	/* NOTE: big-endian */
#define FSL_SOC_USB_AGECNTTHRSH	0x408	/* NOTE: big-endian */
#define FSL_SOC_USB_PRICTRL	0x40c	/* NOTE: big-endian */
#define FSL_SOC_USB_SICTRL	0x410	/* NOTE: big-endian */
#define FSL_SOC_USB_CTRL	0x500	/* NOTE: big-endian */
#define CTRL_UTMI_PHY_EN	(1<<9)
#define CTRL_PHY_CLK_VALID	(1 << 17)
#define SNOOP_SIZE_2GB		0x1e

/* control Register Bit Masks */
#define CONTROL_REGISTER_W1C_MASK       0x00020000  /* W1C: PHY_CLK_VALID */
#define ULPI_INT_EN             (1<<0)
#define WU_INT_EN               (1<<1)
#define USB_CTRL_USB_EN         (1<<2)
#define LINE_STATE_FILTER__EN   (1<<3)
#define KEEP_OTG_ON             (1<<4)
#define OTG_PORT                (1<<5)
#define PLL_RESET               (1<<8)
#define UTMI_PHY_EN             (1<<9)
#define ULPI_PHY_CLK_SEL        (1<<10)
#define PHY_CLK_VALID		(1<<17)
#endif				/* _EHCI_FSL_H */
Not tainted 4.1.13-00510-g9d91424 #2 [ 240.676078] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 240.683922] partprobe D c047504c 0 564 486 0x00000000 [ 240.690318] [<c047504c>] (__schedule) from [<c04754a0>] (schedule+0x40/0x98) [ 240.697396] [<c04754a0>] (schedule) from [<c0477d40>] (schedule_timeout+0x148/0x188) [ 240.705149] [<c0477d40>] (schedule_timeout) from [<c0476040>] (wait_for_common+0xa4/0x170) [ 240.713446] [<c0476040>] (wait_for_common) from [<c01f3300>] (submit_bio_wait+0x58/0x64) [ 240.721571] [<c01f3300>] (submit_bio_wait) from [<c01fbbd8>] (blkdev_issue_flush+0x60/0x88) [ 240.729957] [<c01fbbd8>] (blkdev_issue_flush) from [<c010ff84>] (blkdev_fsync+0x34/0x44) [ 240.738083] [<c010ff84>] (blkdev_fsync) from [<c0109594>] (do_fsync+0x3c/0x64) [ 240.745319] [<c0109594>] (do_fsync) from [<c000ffc0>] (ret_fast_syscall+0x0/0x3c) .. Here is the detailed sequence showing when this issue may happen: 1) At probe time, mmci device is initialized and card busy detection based on DAT[0] monitoring is enabled. 2) Later during run time, since card reported to support internal caches, a MMCI_SWITCH command is sent to eMMC device with FLUSH_CACHE operation. On receiving this command, eMMC may enter busy state (for a relatively short time in the case of the dead-lock). 3) Then mmci interrupt is raised and mmci_irq() is called: MMCISTATUS register is read and is equal to 0x01000440. So the following status bits are set: - MCI_CMDRESPEND (= 6) - MCI_DATABLOCKEND (= 10) - MCI_ST_CARDBUSY (= 24) Since MMCIMASK0 register is 0x3FF, status variable is set to 0x00000040 and BIT MCI_CMDRESPEND is cleared by writing MMCICLEAR register. Then mmci_cmd_irq() is called. Considering the following conditions: - host->busy_status is 0, - this is a "busy response", - reading again MMCISTATUS register gives 0x1000400, MMCIMASK0 is updated to unmask MCI_ST_BUSYEND bit. Thus, MMCIMASK0 is set to 0x010003FF and host->busy_status is set to wait for busy end completion. Back again in status loop of mmci_irq(), we quickly go through mmci_data_irq() as there are no data in that case. And we finally go through following test at the end of while(status) loop: /* * Don't poll for busy completion in irq context. */ if (host->variant->busy_detect && host->busy_status) status &= ~host->variant->busy_detect_flag; Because status variable is not yet null (is equal to 0x40), we do not leave interrupt context yet but we loop again into while(status) loop. So we run across following steps: a) MMCISTATUS register is read again and this time is equal to 0x01000400. So that following bits are set: - MCI_DATABLOCKEND (= 10) - MCI_ST_CARDBUSY (= 24) Since MMCIMASK0 register is equal to 0x010003FF: b) status variable is set to 0x01000000. c) MCI_ST_CARDBUSY bit is cleared by writing MMCICLEAR register. Then, mmci_cmd_irq() is called one more time. Since host->busy_status is set and that MCI_ST_CARDBUSY is set in status variable, we just return from this function. Back again in mmci_irq(), status variable is set to 0 and we finally leave the while(status) loop. As a result we leave interrupt context, waiting for busy end interrupt event. Now, consider that busy end completion is raised IN BETWEEN steps 3.a) and 3.c). In such a case, we may mistakenly clear busy end interrupt at step 3.c) while it has not yet been processed. This will result in mmc command to wait forever for a busy end completion that will never happen. To fix the problem, this patch implements the following changes: Considering that the mmci seems to be triggering the IRQ on both edges while monitoring DAT0 for busy completion and that same status bit is used to monitor start and end of busy detection, special care must be taken to make sure that both start and end interrupts are always cleared one after the other. 1) Clearing of card busy bit is moved in mmc_cmd_irq() function where unmasking of busy end bit is effectively handled. 2) Just before unmasking busy end event, busy start event is cleared by writing card busy bit in MMCICLEAR register. 3) Finally, once we are no more busy with a command, busy end event is cleared writing again card busy bit in MMCICLEAR register. This patch has been tested with the ST Accordo5 machine, not yet supported upstream but relies on the mmci driver. Signed-off-by: Sarang Mairal <sarang.mairal@garmin.com> Signed-off-by: Jean-Nicolas Graux <jean-nicolas.graux@st.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/usb/serial/keyspan.h')