Merge "usb: gadget: set appropriate max_ratio while entering and exiting UMS" (9bbb6d81) · Commits · e / devices / android_kernel_sony_msm8994

drivers/usb/gadget/storage_common.c

+36 −0

Original line number	Diff line number	Diff line
		@@ -140,6 +140,7 @@ struct fsg_lun {

		unsigned int blkbits; /* Bits of logical block size of bound block device */
		unsigned int blksize; /* logical block size of bound block device */
		unsigned int max_ratio;
		struct device dev;
		#ifdef CONFIG_USB_MSC_PROFILING
		spinlock_t lock;
		@@ -189,6 +190,19 @@ MODULE_PARM_DESC(num_buffers, "Number of pipeline buffers");
		#endif /* CONFIG_USB_DEBUG */
		#endif /* CONFIG_USB_CSW_HACK */

		/*
		* uicc_ums_max_ratio is used to set the max ratio for UICC block device when
		* operating in UMS mode. We want to keep this max_ratio as minimum as possible
		* in USM mode and with max_ratio as 1 we are meeting throughput numbers and no
		* functional issues Max ratio for UICC devices in UMS mode, hence a default
		* value of 1 is set for this
		*/

		#define UICC_UMS_MAX_RATIO 1
		static unsigned int uicc_ums_max_ratio = UICC_UMS_MAX_RATIO;
		module_param(uicc_ums_max_ratio, uint, S_IRUGO \| S_IWUSR);
		MODULE_PARM_DESC(uicc_ums_max_ratio, "max ratio in UMS mode for UICC device");

		/* check if fsg_num_buffers is within a valid range */
		static inline int fsg_num_buffers_validate(void)
		{
		@@ -418,7 +432,17 @@ static struct usb_gadget_strings fsg_stringtab = {

		static void fsg_lun_close(struct fsg_lun *curlun)
		{
		struct inode *inode = NULL;
		struct backing_dev_info *bdi;

		if (curlun->filp) {
		inode = file_inode(curlun->filp);
		bdi = &inode->i_bdev->bd_queue->backing_dev_info;

		if ((bdi->capabilities & BDI_CAP_STRICTLIMIT) &&
		bdi_set_max_ratio(bdi, curlun->max_ratio))
		pr_debug("%s, error in setting max_ratio\n", __func__);

		LDBG(curlun, "close backing file\n");
		fput(curlun->filp);
		curlun->filp = NULL;
		@@ -432,6 +456,7 @@ static int fsg_lun_open(struct fsg_lun curlun, const char filename)
		struct file *filp = NULL;
		int rc = -EINVAL;
		struct inode *inode = NULL;
		struct backing_dev_info *bdi;
		loff_t size;
		loff_t num_sectors;
		loff_t min_sectors;
		@@ -516,6 +541,17 @@ static int fsg_lun_open(struct fsg_lun curlun, const char filename)
		curlun->filp = filp;
		curlun->file_length = size;
		curlun->num_sectors = num_sectors;

		bdi = &inode->i_bdev->bd_queue->backing_dev_info;

		if (bdi->capabilities & BDI_CAP_STRICTLIMIT) {
		curlun->max_ratio = bdi->max_ratio;
		curlun->nofua = 1;

		if (bdi_set_max_ratio(bdi, uicc_ums_max_ratio))
		pr_debug("%s, error in setting max_ratio\n", __func__);
		}

		LDBG(curlun, "open backing file: %s\n", filename);
		return 0;