From c900eff30a14ecf209ee7a17a7c3c54890694ce6 Mon Sep 17 00:00:00 2001 From: Jussi Kivilinna Date: Mon, 20 Jun 2011 14:42:44 +0300 Subject: [PATCH] zd1211rw: handle lost read-reg interrupts Device losses read-reg interrupts. By looking at usbmon it appears that USB_INT_ID_RETRY_FAILED can override USB_INT_ID_REGS. This causes read command to timeout, usually under heavy TX. Fix by retrying read registers again if USB_INT_ID_RETRY_FAILED is received while waiting for USB_INT_ID_REGS. However USB_INT_ID_REGS is not always lost but is received after USB_INT_ID_RETRY_FAILED and is usually received by the retried read command. USB_INT_ID_REGS of the retry is then left unhandled and might be received by next read command. Handle this by ignoring previous USB_INT_ID_REGS that doesn't match current read command request. Signed-off-by: Jussi Kivilinna Signed-off-by: John W. Linville --- drivers/net/wireless/zd1211rw/zd_usb.c | 125 +++++++++++++++++++++---- drivers/net/wireless/zd1211rw/zd_usb.h | 5 +- 2 files changed, 109 insertions(+), 21 deletions(-) diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c index 621c2cc9fc85..cf0d69dd7be5 100644 --- a/drivers/net/wireless/zd1211rw/zd_usb.c +++ b/drivers/net/wireless/zd1211rw/zd_usb.c @@ -111,6 +111,9 @@ MODULE_DEVICE_TABLE(usb, usb_ids); #define FW_ZD1211_PREFIX "zd1211/zd1211_" #define FW_ZD1211B_PREFIX "zd1211/zd1211b_" +static bool check_read_regs(struct zd_usb *usb, struct usb_req_read_regs *req, + unsigned int count); + /* USB device initialization */ static void int_urb_complete(struct urb *urb); @@ -365,6 +368,20 @@ exit: #define urb_dev(urb) (&(urb)->dev->dev) +static inline void handle_regs_int_override(struct urb *urb) +{ + struct zd_usb *usb = urb->context; + struct zd_usb_interrupt *intr = &usb->intr; + + spin_lock(&intr->lock); + if (atomic_read(&intr->read_regs_enabled)) { + atomic_set(&intr->read_regs_enabled, 0); + intr->read_regs_int_overridden = 1; + complete(&intr->read_regs.completion); + } + spin_unlock(&intr->lock); +} + static inline void handle_regs_int(struct urb *urb) { struct zd_usb *usb = urb->context; @@ -383,25 +400,45 @@ static inline void handle_regs_int(struct urb *urb) USB_MAX_EP_INT_BUFFER); spin_unlock(&mac->lock); schedule_work(&mac->process_intr); - } else if (intr->read_regs_enabled) { - intr->read_regs.length = len = urb->actual_length; - + } else if (atomic_read(&intr->read_regs_enabled)) { + len = urb->actual_length; + intr->read_regs.length = urb->actual_length; if (len > sizeof(intr->read_regs.buffer)) len = sizeof(intr->read_regs.buffer); + memcpy(intr->read_regs.buffer, urb->transfer_buffer, len); - intr->read_regs_enabled = 0; + + /* Sometimes USB_INT_ID_REGS is not overridden, but comes after + * USB_INT_ID_RETRY_FAILED. Read-reg retry then gets this + * delayed USB_INT_ID_REGS, but leaves USB_INT_ID_REGS of + * retry unhandled. Next read-reg command then might catch + * this wrong USB_INT_ID_REGS. Fix by ignoring wrong reads. + */ + if (!check_read_regs(usb, intr->read_regs.req, + intr->read_regs.req_count)) + goto out; + + atomic_set(&intr->read_regs_enabled, 0); + intr->read_regs_int_overridden = 0; complete(&intr->read_regs.completion); + goto out; } out: spin_unlock(&intr->lock); + + /* CR_INTERRUPT might override read_reg too. */ + if (int_num == CR_INTERRUPT && atomic_read(&intr->read_regs_enabled)) + handle_regs_int_override(urb); } static void int_urb_complete(struct urb *urb) { int r; struct usb_int_header *hdr; + struct zd_usb *usb; + struct zd_usb_interrupt *intr; switch (urb->status) { case 0: @@ -430,6 +467,14 @@ static void int_urb_complete(struct urb *urb) goto resubmit; } + /* USB_INT_ID_RETRY_FAILED triggered by tx-urb submit can override + * pending USB_INT_ID_REGS causing read command timeout. + */ + usb = urb->context; + intr = &usb->intr; + if (hdr->id != USB_INT_ID_REGS && atomic_read(&intr->read_regs_enabled)) + handle_regs_int_override(urb); + switch (hdr->id) { case USB_INT_ID_REGS: handle_regs_int(urb); @@ -1129,6 +1174,7 @@ static inline void init_usb_interrupt(struct zd_usb *usb) spin_lock_init(&intr->lock); intr->interval = int_urb_interval(zd_usb_to_usbdev(usb)); init_completion(&intr->read_regs.completion); + atomic_set(&intr->read_regs_enabled, 0); intr->read_regs.cr_int_addr = cpu_to_le16((u16)CR_INTERRUPT); } @@ -1563,12 +1609,16 @@ static int usb_int_regs_length(unsigned int count) return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data); } -static void prepare_read_regs_int(struct zd_usb *usb) +static void prepare_read_regs_int(struct zd_usb *usb, + struct usb_req_read_regs *req, + unsigned int count) { struct zd_usb_interrupt *intr = &usb->intr; spin_lock_irq(&intr->lock); - intr->read_regs_enabled = 1; + atomic_set(&intr->read_regs_enabled, 1); + intr->read_regs.req = req; + intr->read_regs.req_count = count; INIT_COMPLETION(intr->read_regs.completion); spin_unlock_irq(&intr->lock); } @@ -1578,22 +1628,18 @@ static void disable_read_regs_int(struct zd_usb *usb) struct zd_usb_interrupt *intr = &usb->intr; spin_lock_irq(&intr->lock); - intr->read_regs_enabled = 0; + atomic_set(&intr->read_regs_enabled, 0); spin_unlock_irq(&intr->lock); } -static int get_results(struct zd_usb *usb, u16 *values, - struct usb_req_read_regs *req, unsigned int count) +static bool check_read_regs(struct zd_usb *usb, struct usb_req_read_regs *req, + unsigned int count) { - int r; int i; struct zd_usb_interrupt *intr = &usb->intr; struct read_regs_int *rr = &intr->read_regs; struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer; - spin_lock_irq(&intr->lock); - - r = -EIO; /* The created block size seems to be larger than expected. * However results appear to be correct. */ @@ -1601,13 +1647,14 @@ static int get_results(struct zd_usb *usb, u16 *values, dev_dbg_f(zd_usb_dev(usb), "error: actual length %d less than expected %d\n", rr->length, usb_int_regs_length(count)); - goto error_unlock; + return false; } + if (rr->length > sizeof(rr->buffer)) { dev_dbg_f(zd_usb_dev(usb), "error: actual length %d exceeds buffer size %zu\n", rr->length, sizeof(rr->buffer)); - goto error_unlock; + return false; } for (i = 0; i < count; i++) { @@ -1617,8 +1664,39 @@ static int get_results(struct zd_usb *usb, u16 *values, "rd[%d] addr %#06hx expected %#06hx\n", i, le16_to_cpu(rd->addr), le16_to_cpu(req->addr[i])); - goto error_unlock; + return false; } + } + + return true; +} + +static int get_results(struct zd_usb *usb, u16 *values, + struct usb_req_read_regs *req, unsigned int count, + bool *retry) +{ + int r; + int i; + struct zd_usb_interrupt *intr = &usb->intr; + struct read_regs_int *rr = &intr->read_regs; + struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer; + + spin_lock_irq(&intr->lock); + + r = -EIO; + + /* Read failed because firmware bug? */ + *retry = !!intr->read_regs_int_overridden; + if (*retry) + goto error_unlock; + + if (!check_read_regs(usb, req, count)) { + dev_dbg_f(zd_usb_dev(usb), "error: invalid read regs\n"); + goto error_unlock; + } + + for (i = 0; i < count; i++) { + struct reg_data *rd = ®s->regs[i]; values[i] = le16_to_cpu(rd->value); } @@ -1631,11 +1709,11 @@ error_unlock: int zd_usb_ioread16v(struct zd_usb *usb, u16 *values, const zd_addr_t *addresses, unsigned int count) { - int r; - int i, req_len, actual_req_len; + int r, i, req_len, actual_req_len, try_count = 0; struct usb_device *udev; struct usb_req_read_regs *req = NULL; unsigned long timeout; + bool retry = false; if (count < 1) { dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n"); @@ -1671,8 +1749,10 @@ int zd_usb_ioread16v(struct zd_usb *usb, u16 *values, for (i = 0; i < count; i++) req->addr[i] = cpu_to_le16((u16)addresses[i]); +retry_read: + try_count++; udev = zd_usb_to_usbdev(usb); - prepare_read_regs_int(usb); + prepare_read_regs_int(usb, req, count); r = zd_ep_regs_out_msg(udev, req, req_len, &actual_req_len, 50 /*ms*/); if (r) { dev_dbg_f(zd_usb_dev(usb), @@ -1696,7 +1776,12 @@ int zd_usb_ioread16v(struct zd_usb *usb, u16 *values, goto error; } - r = get_results(usb, values, req, count); + r = get_results(usb, values, req, count, &retry); + if (retry && try_count < 20) { + dev_dbg_f(zd_usb_dev(usb), "read retry, tries so far: %d\n", + try_count); + goto retry_read; + } error: return r; } diff --git a/drivers/net/wireless/zd1211rw/zd_usb.h b/drivers/net/wireless/zd1211rw/zd_usb.h index bf942843b733..99193b456a79 100644 --- a/drivers/net/wireless/zd1211rw/zd_usb.h +++ b/drivers/net/wireless/zd1211rw/zd_usb.h @@ -144,6 +144,8 @@ struct usb_int_retry_fail { struct read_regs_int { struct completion completion; + struct usb_req_read_regs *req; + unsigned int req_count; /* Stores the USB int structure and contains the USB address of the * first requested register before request. */ @@ -169,7 +171,8 @@ struct zd_usb_interrupt { void *buffer; dma_addr_t buffer_dma; int interval; - u8 read_regs_enabled:1; + atomic_t read_regs_enabled; + u8 read_regs_int_overridden:1; }; static inline struct usb_int_regs *get_read_regs(struct zd_usb_interrupt *intr) -- 2.20.1