diff options
Diffstat (limited to 'drivers/block/ub.c')
| -rw-r--r-- | drivers/block/ub.c | 211 |
1 files changed, 170 insertions, 41 deletions
diff --git a/drivers/block/ub.c b/drivers/block/ub.c index 685f061..a026567 100644 --- a/drivers/block/ub.c +++ b/drivers/block/ub.c @@ -23,6 +23,7 @@ * -- Exterminate P3 printks * -- Resove XXX's * -- Redo "benh's retries", perhaps have spin-up code to handle them. V:D=? + * -- CLEAR, CLR2STS, CLRRS seem to be ripe for refactoring. */ #include <linux/kernel.h> #include <linux/module.h> @@ -38,6 +39,73 @@ #define UB_MAJOR 180 /* + * The command state machine is the key model for understanding of this driver. + * + * The general rule is that all transitions are done towards the bottom + * of the diagram, thus preventing any loops. + * + * An exception to that is how the STAT state is handled. A counter allows it + * to be re-entered along the path marked with [C]. + * + * +--------+ + * ! INIT ! + * +--------+ + * ! + * ub_scsi_cmd_start fails ->--------------------------------------\ + * ! ! + * V ! + * +--------+ ! + * ! CMD ! ! + * +--------+ ! + * ! +--------+ ! + * was -EPIPE -->-------------------------------->! CLEAR ! ! + * ! +--------+ ! + * ! ! ! + * was error -->------------------------------------- ! --------->\ + * ! ! ! + * /--<-- cmd->dir == NONE ? ! ! + * ! ! ! ! + * ! V ! ! + * ! +--------+ ! ! + * ! ! DATA ! ! ! + * ! +--------+ ! ! + * ! ! +---------+ ! ! + * ! was -EPIPE -->--------------->! CLR2STS ! ! ! + * ! ! +---------+ ! ! + * ! ! ! ! ! + * ! ! was error -->---- ! --------->\ + * ! was error -->--------------------- ! ------------- ! --------->\ + * ! ! ! ! ! + * ! V ! ! ! + * \--->+--------+ ! ! ! + * ! STAT !<--------------------------/ ! ! + * /--->+--------+ ! ! + * ! ! ! ! + * [C] was -EPIPE -->-----------\ ! ! + * ! ! ! ! ! + * +<---- len == 0 ! ! ! + * ! ! ! ! ! + * ! was error -->--------------------------------------!---------->\ + * ! ! ! ! ! + * +<---- bad CSW ! ! ! + * +<---- bad tag ! ! ! + * ! ! V ! ! + * ! ! +--------+ ! ! + * ! ! ! CLRRS ! ! ! + * ! ! +--------+ ! ! + * ! ! ! ! ! + * \------- ! --------------------[C]--------\ ! ! + * ! ! ! ! + * cmd->error---\ +--------+ ! ! + * ! +--------------->! SENSE !<----------/ ! + * STAT_FAIL----/ +--------+ ! + * ! ! V + * ! V +--------+ + * \--------------------------------\--------------------->! DONE ! + * +--------+ + */ + +/* * Definitions which have to be scattered once we understand the layout better. */ @@ -91,8 +159,6 @@ struct bulk_cs_wrap { #define US_BULK_CS_WRAP_LEN 13 #define US_BULK_CS_SIGN 0x53425355 /* spells out 'USBS' */ -/* This is for Olympus Camedia digital cameras */ -#define US_BULK_CS_OLYMPUS_SIGN 0x55425355 /* spells out 'USBU' */ #define US_BULK_STAT_OK 0 #define US_BULK_STAT_FAIL 1 #define US_BULK_STAT_PHASE 2 @@ -135,6 +201,7 @@ enum ub_scsi_cmd_state { UB_CMDST_CLR2STS, /* Clearing before requesting status */ UB_CMDST_STAT, /* Status phase */ UB_CMDST_CLEAR, /* Clearing a stall (halt, actually) */ + UB_CMDST_CLRRS, /* Clearing before retrying status */ UB_CMDST_SENSE, /* Sending Request Sense */ UB_CMDST_DONE /* Final state */ }; @@ -146,6 +213,7 @@ static char *ub_scsi_cmd_stname[] = { "c2s", "sts", "clr", + "crs", "Sen", "fin" }; @@ -316,6 +384,7 @@ struct ub_dev { struct urb work_urb; struct timer_list work_timer; int last_pipe; /* What might need clearing */ + __le32 signature; /* Learned signature */ struct bulk_cb_wrap work_bcb; struct bulk_cs_wrap work_bcs; struct usb_ctrlrequest work_cr; @@ -339,8 +408,9 @@ static void ub_scsi_action(unsigned long _dev); static void ub_scsi_dispatch(struct ub_dev *sc); static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc); -static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd); +static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd); +static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int stalled_pipe); @@ -1085,6 +1155,28 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd) ub_state_stat(sc, cmd); + } else if (cmd->state == UB_CMDST_CLRRS) { + if (urb->status == -EPIPE) { + /* + * STALL while clearning STALL. + * The control pipe clears itself - nothing to do. + * XXX Might try to reset the device here and retry. + */ + printk(KERN_NOTICE "%s: stall on control pipe\n", + sc->name); + goto Bad_End; + } + + /* + * We ignore the result for the halt clear. + */ + + /* reset the endpoint toggle */ + usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe), + usb_pipeout(sc->last_pipe), 0); + + ub_state_stat_counted(sc, cmd); + } else if (cmd->state == UB_CMDST_CMD) { if (urb->status == -EPIPE) { rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe); @@ -1190,52 +1282,57 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd) */ goto Bad_End; } - cmd->state = UB_CMDST_CLEAR; + + /* + * Having a stall when getting CSW is an error, so + * make sure uppper levels are not oblivious to it. + */ + cmd->error = -EIO; /* A cheap trick... */ + + cmd->state = UB_CMDST_CLRRS; ub_cmdtr_state(sc, cmd); return; } + if (urb->status == -EOVERFLOW) { + /* + * XXX We are screwed here. Retrying is pointless, + * because the pipelined data will not get in until + * we read with a big enough buffer. We must reset XXX. + */ + goto Bad_End; + } if (urb->status != 0) goto Bad_End; if (urb->actual_length == 0) { - /* - * Some broken devices add unnecessary zero-length - * packets to the end of their data transfers. - * Such packets show up as 0-length CSWs. If we - * encounter such a thing, try to read the CSW again. - */ - if (++cmd->stat_count >= 4) { - printk(KERN_NOTICE "%s: unable to get CSW\n", - sc->name); - goto Bad_End; - } - __ub_state_stat(sc, cmd); + ub_state_stat_counted(sc, cmd); return; } /* * Check the returned Bulk protocol status. + * The status block has to be validated first. */ bcs = &sc->work_bcs; - rc = le32_to_cpu(bcs->Residue); - if (rc != cmd->len - cmd->act_len) { + + if (sc->signature == cpu_to_le32(0)) { /* - * It is all right to transfer less, the caller has - * to check. But it's not all right if the device - * counts disagree with our counts. + * This is the first reply, so do not perform the check. + * Instead, remember the signature the device uses + * for future checks. But do not allow a nul. */ - /* P3 */ printk("%s: resid %d len %d act %d\n", - sc->name, rc, cmd->len, cmd->act_len); - goto Bad_End; - } - -#if 0 - if (bcs->Signature != cpu_to_le32(US_BULK_CS_SIGN) && - bcs->Signature != cpu_to_le32(US_BULK_CS_OLYMPUS_SIGN)) { - /* Windows ignores signatures, so do we. */ + sc->signature = bcs->Signature; + if (sc->signature == cpu_to_le32(0)) { + ub_state_stat_counted(sc, cmd); + return; + } + } else { + if (bcs->Signature != sc->signature) { + ub_state_stat_counted(sc, cmd); + return; + } } -#endif if (bcs->Tag != cmd->tag) { /* @@ -1245,16 +1342,22 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd) * commands and reply at commands we timed out before. * Without flushing these replies we loop forever. */ - if (++cmd->stat_count >= 4) { - printk(KERN_NOTICE "%s: " - "tag mismatch orig 0x%x reply 0x%x\n", - sc->name, cmd->tag, bcs->Tag); - goto Bad_End; - } - __ub_state_stat(sc, cmd); + ub_state_stat_counted(sc, cmd); return; } + rc = le32_to_cpu(bcs->Residue); + if (rc != cmd->len - cmd->act_len) { + /* + * It is all right to transfer less, the caller has + * to check. But it's not all right if the device + * counts disagree with our counts. + */ + /* P3 */ printk("%s: resid %d len %d act %d\n", + sc->name, rc, cmd->len, cmd->act_len); + goto Bad_End; + } + switch (bcs->Status) { case US_BULK_STAT_OK: break; @@ -1272,6 +1375,10 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd) } /* Not zeroing error to preserve a babble indicator */ + if (cmd->error != 0) { + ub_state_sense(sc, cmd); + return; + } cmd->state = UB_CMDST_DONE; ub_cmdtr_state(sc, cmd); ub_cmdq_pop(sc); @@ -1310,7 +1417,7 @@ static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc) * Factorization helper for the command state machine: * Submit a CSW read. */ -static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd) +static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { int rc; @@ -1328,11 +1435,12 @@ static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd) /* XXX Clear stalls */ ub_complete(&sc->work_done); ub_state_done(sc, cmd, rc); - return; + return -1; } sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT; add_timer(&sc->work_timer); + return 0; } /* @@ -1341,7 +1449,9 @@ static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd) */ static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { - __ub_state_stat(sc, cmd); + + if (__ub_state_stat(sc, cmd) != 0) + return; cmd->stat_count = 0; cmd->state = UB_CMDST_STAT; @@ -1350,6 +1460,25 @@ static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd) /* * Factorization helper for the command state machine: + * Submit a CSW read and go to STAT state with counter (along [C] path). + */ +static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd) +{ + + if (++cmd->stat_count >= 4) { + ub_state_sense(sc, cmd); + return; + } + + if (__ub_state_stat(sc, cmd) != 0) + return; + + cmd->state = UB_CMDST_STAT; + ub_cmdtr_state(sc, cmd); +} + +/* + * Factorization helper for the command state machine: * Submit a REQUEST SENSE and go to SENSE state. */ static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd) |
