From mdharm@multivac.one-eyed-alien.net Mon Jun 6 17:24:01 2005 Date: Mon, 6 Jun 2005 17:21:41 -0700 From: Matthew Dharm To: USB Storage List , Greg KH Subject: USB Storage: port reset on transport error Message-ID: <20050607002141.GC8689@one-eyed-alien.net> This patch causes a port reset whenever there's a transport error or abort. If that fails it reverts back to doing a mass-storage device reset. It started life as as497 and was rediffed by me. This makes error recovery a lot quicker and more reliable. Signed-off-by: Alan Stern Signed-off-by: Matthew Dharm Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/scsiglue.c | 45 +++++------------- drivers/usb/storage/scsiglue.h | 1 drivers/usb/storage/transport.c | 99 +++++++++++++++++++++++++++------------- drivers/usb/storage/transport.h | 1 4 files changed, 82 insertions(+), 64 deletions(-) --- gregkh-2.6.orig/drivers/usb/storage/scsiglue.c 2005-06-20 13:05:28.000000000 -0700 +++ gregkh-2.6/drivers/usb/storage/scsiglue.c 2005-06-20 13:10:01.000000000 -0700 @@ -255,50 +255,23 @@ /* lock the device pointers and do the reset */ down(&(us->dev_semaphore)); - if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { - result = FAILED; - US_DEBUGP("No reset during disconnect\n"); - } else - result = us->transport_reset(us); + result = us->transport_reset(us); up(&(us->dev_semaphore)); - return result; + return result < 0 ? FAILED : SUCCESS; } -/* This resets the device's USB port. */ -/* It refuses to work if there's more than one interface in - * the device, so that other users are not affected. */ +/* Simulate a SCSI bus reset by resetting the device's USB port. */ /* This is always called with scsi_lock(host) held */ static int bus_reset(struct scsi_cmnd *srb) { struct us_data *us = host_to_us(srb->device->host); - int result, rc; + int result; US_DEBUGP("%s called\n", __FUNCTION__); - /* The USB subsystem doesn't handle synchronisation between - * a device's several drivers. Therefore we reset only devices - * with just one interface, which we of course own. */ - down(&(us->dev_semaphore)); - if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { - result = -EIO; - US_DEBUGP("No reset during disconnect\n"); - } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) { - result = -EBUSY; - US_DEBUGP("Refusing to reset a multi-interface device\n"); - } else { - rc = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); - if (rc < 0) { - US_DEBUGP("unable to lock device for reset: %d\n", rc); - result = rc; - } else { - result = usb_reset_device(us->pusb_dev); - if (rc) - usb_unlock_device(us->pusb_dev); - US_DEBUGP("usb_reset_device returns %d\n", result); - } - } + result = usb_stor_port_reset(us); up(&(us->dev_semaphore)); /* lock the host for the return */ @@ -320,6 +293,14 @@ } } +/* Report a driver-initiated bus reset to the SCSI layer. + * Calling this for a SCSI-initiated reset is unnecessary but harmless. + * The caller must own the SCSI host lock. */ +void usb_stor_report_bus_reset(struct us_data *us) +{ + scsi_report_bus_reset(us_to_host(us), 0); +} + /*********************************************************************** * /proc/scsi/ functions ***********************************************************************/ --- gregkh-2.6.orig/drivers/usb/storage/scsiglue.h 2005-06-20 13:02:08.000000000 -0700 +++ gregkh-2.6/drivers/usb/storage/scsiglue.h 2005-06-20 13:07:26.000000000 -0700 @@ -42,6 +42,7 @@ #define _SCSIGLUE_H_ extern void usb_stor_report_device_reset(struct us_data *us); +extern void usb_stor_report_bus_reset(struct us_data *us); extern unsigned char usb_stor_sense_invalidCDB[18]; extern struct scsi_host_template usb_stor_host_template; --- gregkh-2.6.orig/drivers/usb/storage/transport.c 2005-06-20 13:07:18.000000000 -0700 +++ gregkh-2.6/drivers/usb/storage/transport.c 2005-06-20 13:07:26.000000000 -0700 @@ -541,15 +541,15 @@ */ if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) { US_DEBUGP("-- command was aborted\n"); - goto Handle_Abort; + srb->result = DID_ABORT << 16; + goto Handle_Errors; } /* if there is a transport error, reset and don't auto-sense */ if (result == USB_STOR_TRANSPORT_ERROR) { US_DEBUGP("-- transport indicates error, resetting\n"); - us->transport_reset(us); srb->result = DID_ERROR << 16; - return; + goto Handle_Errors; } /* if the transport provided its own sense data, don't auto-sense */ @@ -669,7 +669,8 @@ if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) { US_DEBUGP("-- auto-sense aborted\n"); - goto Handle_Abort; + srb->result = DID_ABORT << 16; + goto Handle_Errors; } if (temp_result != USB_STOR_TRANSPORT_GOOD) { US_DEBUGP("-- auto-sense failure\n"); @@ -678,9 +679,9 @@ * multi-target device, since failure of an * auto-sense is perfectly valid */ - if (!(us->flags & US_FL_SCM_MULT_TARG)) - us->transport_reset(us); srb->result = DID_ERROR << 16; + if (!(us->flags & US_FL_SCM_MULT_TARG)) + goto Handle_Errors; return; } @@ -721,12 +722,28 @@ return; - /* abort processing: the bulk-only transport requires a reset - * following an abort */ - Handle_Abort: - srb->result = DID_ABORT << 16; - if (us->protocol == US_PR_BULK) + /* Error and abort processing: try to resynchronize with the device + * by issuing a port reset. If that fails, try a class-specific + * device reset. */ + Handle_Errors: + + /* Let the SCSI layer know we are doing a reset, set the + * RESETTING bit, and clear the ABORTING bit so that the reset + * may proceed. */ + scsi_lock(us_to_host(us)); + usb_stor_report_bus_reset(us); + set_bit(US_FLIDX_RESETTING, &us->flags); + clear_bit(US_FLIDX_ABORTING, &us->flags); + scsi_unlock(us_to_host(us)); + + result = usb_stor_port_reset(us); + if (result < 0) { + scsi_lock(us_to_host(us)); + usb_stor_report_device_reset(us); + scsi_unlock(us_to_host(us)); us->transport_reset(us); + } + clear_bit(US_FLIDX_RESETTING, &us->flags); } /* Stop the current URB transfer */ @@ -1134,24 +1151,18 @@ { int result; int result2; - int rc = FAILED; - /* Let the SCSI layer know we are doing a reset, set the - * RESETTING bit, and clear the ABORTING bit so that the reset - * may proceed. - */ - scsi_lock(us_to_host(us)); - usb_stor_report_device_reset(us); - set_bit(US_FLIDX_RESETTING, &us->flags); - clear_bit(US_FLIDX_ABORTING, &us->flags); - scsi_unlock(us_to_host(us)); + if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { + US_DEBUGP("No reset during disconnect\n"); + return -EIO; + } result = usb_stor_control_msg(us, us->send_ctrl_pipe, request, requesttype, value, index, data, size, 5*HZ); if (result < 0) { US_DEBUGP("Soft reset failed: %d\n", result); - goto Done; + return result; } /* Give the device some time to recover from the reset, @@ -1161,7 +1172,7 @@ HZ*6); if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { US_DEBUGP("Reset interrupted by disconnect\n"); - goto Done; + return -EIO; } US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n"); @@ -1173,16 +1184,11 @@ /* return a result code based on the result of the clear-halts */ if (result >= 0) result = result2; - if (result < 0) { + if (result < 0) US_DEBUGP("Soft reset failed\n"); - goto Done; - } - US_DEBUGP("Soft reset done\n"); - rc = SUCCESS; - - Done: - clear_bit(US_FLIDX_RESETTING, &us->flags); - return rc; + else + US_DEBUGP("Soft reset done\n"); + return result; } /* This issues a CB[I] Reset to the device in question @@ -1212,3 +1218,32 @@ USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, us->ifnum, NULL, 0); } + +/* Issue a USB port reset to the device. But don't do anything if + * there's more than one interface in the device, so that other users + * are not affected. */ +int usb_stor_port_reset(struct us_data *us) +{ + int result, rc; + + if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { + result = -EIO; + US_DEBUGP("No reset during disconnect\n"); + } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) { + result = -EBUSY; + US_DEBUGP("Refusing to reset a multi-interface device\n"); + } else { + result = rc = + usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); + if (result < 0) { + US_DEBUGP("unable to lock device for reset: %d\n", + result); + } else { + result = usb_reset_device(us->pusb_dev); + if (rc) + usb_unlock_device(us->pusb_dev); + US_DEBUGP("usb_reset_device returns %d\n", result); + } + } + return result; +} --- gregkh-2.6.orig/drivers/usb/storage/transport.h 2005-06-20 13:02:08.000000000 -0700 +++ gregkh-2.6/drivers/usb/storage/transport.h 2005-06-20 13:07:26.000000000 -0700 @@ -171,4 +171,5 @@ extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe, void *buf, unsigned int length, int use_sg, int *residual); +extern int usb_stor_port_reset(struct us_data *us); #endif