usb: gadget: mass_storage: allow for deeper queue lengths

Instead of allowing a range of 2 to 4 requests,
let's allow the user choose up to 32 requests
as that will give us a better chance of keeping
controller busy.

We still maintain default of 2 so users shouldn't
be affected.

Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index bcf83c0..33834aa 100644 (file)
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -113,7 +113,7 @@ config USB_GADGET_VBUS_DRAW
 
 config USB_GADGET_STORAGE_NUM_BUFFERS
        int "Number of storage pipeline buffers"
-       range 2 4
+       range 2 32
        default 2
        help
           Usually 2 buffers are enough to establish a good buffering

diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
index a6eb537..5277e7c 100644 (file)
--- a/drivers/usb/gadget/function/f_mass_storage.c
+++ b/drivers/usb/gadget/function/f_mass_storage.c
@@ -2662,10 +2662,12 @@ EXPORT_SYMBOL_GPL(fsg_common_put);
 /* check if fsg_num_buffers is within a valid range */
 static inline int fsg_num_buffers_validate(unsigned int fsg_num_buffers)
 {
-       if (fsg_num_buffers >= 2 && fsg_num_buffers <= 4)
+#define FSG_MAX_NUM_BUFFERS    32
+
+       if (fsg_num_buffers >= 2 && fsg_num_buffers <= FSG_MAX_NUM_BUFFERS)
                return 0;
        pr_err("fsg_num_buffers %u is out of range (%d to %d)\n",
-              fsg_num_buffers, 2, 4);
+              fsg_num_buffers, 2, FSG_MAX_NUM_BUFFERS);
        return -EINVAL;
 }