By making that configurable on Kconfig, we won't
need to modify source code when we want to change
the way f_mass_storage behaves for a specific
product.
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
drivers/usb/gadget/Kconfig | 15 +++++++++++++++
drivers/usb/gadget/f_mass_storage.c | 17 ++++++++++-------
drivers/usb/gadget/storage_common.h | 3 ---
3 files changed, 25 insertions(+), 10 deletions(-)
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 0ae2e65..f3b9702 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -127,6 +127,21 @@ config USB_GADGET_STORAGE_NUM_BUFFERS
a module parameter as well.
If unsure, say 2.
+config USB_GADGET_STORAGE_BUFLEN
+ int "Size of each storage pipeline buffer"
+ range 4096 131072
+ default 16384
+ help
+ For USB2-based device controllers, 16KiB of buffer space is
+ usually enough to maintain the HW FIFOs full during an entire
+ session.
+
+ When dealing with USB3 device controllers, however, 16KiB is
+ not enough.
+
+ Change this to match your device requirements. If unsure, say
+ 16384.
+
#
# USB Peripheral Controller Support
#
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index a03ba2c..fee97c9 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -675,7 +675,7 @@ static int do_read(struct fsg_common *common)
* But don't read more than the buffer size.
* And don't try to read past the end of the file.
*/
- amount = min(amount_left, FSG_BUFLEN);
+ amount = min_t(u32, amount_left, CONFIG_USB_GADGET_STORAGE_BUFLEN);
amount = min((loff_t)amount,
curlun->file_length - file_offset);
@@ -825,7 +825,8 @@ static int do_write(struct fsg_common *common)
* Try to get the remaining amount,
* but not more than the buffer size.
*/
- amount = min(amount_left_to_req, FSG_BUFLEN);
+ amount = min_t(u32, amount_left_to_req,
+ CONFIG_USB_GADGET_STORAGE_BUFLEN);
/* Beyond the end of the backing file? */
if (usb_offset >= curlun->file_length) {
@@ -1029,7 +1030,8 @@ static int do_verify(struct fsg_common *common)
* the buffer size.
* And don't try to read past the end of the file.
*/
- amount = min(amount_left, FSG_BUFLEN);
+ amount = min_t(u32, amount_left,
+ CONFIG_USB_GADGET_STORAGE_BUFLEN);
amount = min((loff_t)amount,
curlun->file_length - file_offset);
if (amount == 0) {
@@ -1260,7 +1262,7 @@ static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
} else { /* MODE_SENSE_10 */
buf[3] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
buf += 8;
- limit = 65535; /* Should really be FSG_BUFLEN */
+ limit = 65535; /* Should really be CONFIG_USB_GADGET_STORAGE_BUFLEN */
}
/* No block descriptors */
@@ -1487,7 +1489,8 @@ static int throw_away_data(struct fsg_common *common)
bh = common->next_buffhd_to_fill;
if (bh->state == BUF_STATE_EMPTY
&& common->usb_amount_left > 0) {
- amount = min(common->usb_amount_left, FSG_BUFLEN);
+ amount = min_t(u32, common->usb_amount_left,
+ CONFIG_USB_GADGET_STORAGE_BUFLEN);
/*
* Except at the end of the transfer, amount will be
@@ -2721,7 +2724,7 @@ int fsg_common_set_num_buffers(struct fsg_common *common, unsigned int n)
bh->next = bh + 1;
++bh;
buffhds_first_it:
- bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
+ bh->buf = kmalloc(CONFIG_USB_GADGET_STORAGE_BUFLEN, GFP_KERNEL);
if (unlikely(!bh->buf))
goto error_release;
} while (--i);
@@ -3146,7 +3149,7 @@ static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
fsg_fs_bulk_out_desc.bEndpointAddress;
/* Calculate bMaxBurst, we know packet size is 1024 */
- max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15);
+ max_burst = min_t(u32, CONFIG_USB_GADGET_STORAGE_BUFLEN / 1024, 15);
fsg_ss_bulk_in_desc.bEndpointAddress =
fsg_fs_bulk_in_desc.bEndpointAddress;
diff --git a/drivers/usb/gadget/storage_common.h b/drivers/usb/gadget/storage_common.h
index c74c2fd..4610260 100644
--- a/drivers/usb/gadget/storage_common.h
+++ b/drivers/usb/gadget/storage_common.h
@@ -123,9 +123,6 @@ static inline bool fsg_lun_is_open(struct fsg_lun *curlun)
#define EP0_BUFSIZE 256
#define DELAYED_STATUS (EP0_BUFSIZE + 999) /* An impossibly large value */
-/* Default size of buffer length. */
-#define FSG_BUFLEN ((u32)16384)
-
/* Maximal number of LUNs supported in mass storage function */
#define FSG_MAX_LUNS 8
--
1.8.4.GIT
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