usb: gadget: mass_storage: allow for deeper queue lengths

Felipe Balbi · nsekhar · commit 65a4890633e9 · 2015-09-24T19:09:30.000+05:30
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 &lt;balbi@ti.com&gt;
Signed-off-by: Sekhar Nori &lt;nsekhar@ti.com&gt;
diff --git 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
@@ -2653,10 +2653,12 @@ 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;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -2653,10 +2653,12 @@ EXPORT_SYMBOL_GPL(fsg_common_put);`
`2653`	`2653`	`/* check if fsg_num_buffers is within a valid range */`
`2654`	`2654`	`static inline int fsg_num_buffers_validate(unsigned int fsg_num_buffers)`
`2655`	`2655`	`{`
`2656`		`- if (fsg_num_buffers >= 2 && fsg_num_buffers <= 4)`
	`2656`	`+#define FSG_MAX_NUM_BUFFERS 32`
	`2657`	`+`
	`2658`	`+ if (fsg_num_buffers >= 2 && fsg_num_buffers <= FSG_MAX_NUM_BUFFERS)`
`2657`	`2659`	`return 0;`
`2658`	`2660`	`pr_err("fsg_num_buffers %u is out of range (%d to %d)\n",`
`2659`		`- fsg_num_buffers, 2, 4);`
	`2661`	`+ fsg_num_buffers, 2, FSG_MAX_NUM_BUFFERS);`
`2660`	`2662`	`return -EINVAL;`
`2661`	`2663`	`}`
`2662`	`2664`