From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rajesh Bhagat Date: Wed, 1 Jun 2016 03:47:29 +0000 Subject: [U-Boot] [PATCH 1/2] common: usb_storage : Implement logic to calculate optimal usb maximum trasfer blocks In-Reply-To: <574D7C02.50605@denx.de> References: <1464607435-2639-1-git-send-email-rajesh.bhagat@nxp.com> <1464607435-2639-2-git-send-email-rajesh.bhagat@nxp.com> <574CCFBE.3020808@denx.de> <574D7C02.50605@denx.de> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de > -----Original Message----- > From: Marek Vasut [mailto:marex at denx.de] > Sent: Tuesday, May 31, 2016 5:27 PM > To: Rajesh Bhagat ; u-boot at lists.denx.de > Cc: sjg at chromium.org; york sun ; Sriram Dash > > Subject: Re: [PATCH 1/2] common: usb_storage : Implement logic to calculate > optimal usb maximum trasfer blocks > > On 05/31/2016 05:23 AM, Rajesh Bhagat wrote: > > > > > >> -----Original Message----- > >> From: Marek Vasut [mailto:marex at denx.de] > >> Sent: Tuesday, May 31, 2016 5:12 AM > >> To: Rajesh Bhagat ; u-boot at lists.denx.de > >> Cc: sjg at chromium.org; york sun ; Sriram Dash > >> > >> Subject: Re: [PATCH 1/2] common: usb_storage : Implement logic to > >> calculate optimal usb maximum trasfer blocks > >> > >> On 05/30/2016 01:23 PM, Rajesh Bhagat wrote: > >>> Implements the logic to calculate the optimal usb maximum trasfer > >>> blocks instead of sending USB_MAX_XFER_BLK blocks which is 65535 and > >>> 20 in case of EHCI and other USB protocols respectively. > >>> > >>> It adds an array of trasfer blocks that should be checked for > >>> success starting from minimum to maximum, and rest of the read/write > >>> are performed with that optimal value. It tries to increase/decrease > >>> the blocks in follwing scenarios: > >>> > >>> 1.decrease blocks: when read/write for a particular number of blocks > >>> fails. > >>> 2. increase blocks: when read/write for a particular number of > >>> blocks pass and amount left to trasfer is greater than current > >>> number of blocks. > >>> > >>> Currently changes are done for EHCI where min = 4096 andmax = 65535 > >>> is taken. And for other cases code is left unchanged by keeping min > >>> = max = 20. > >>> > >>> Signed-off-by: Sriram Dash > >>> Signed-off-by: Rajesh Bhagat > >>> --- > >>> common/usb_storage.c | 54 > >> ++++++++++++++++++++++++++++++++++++++++---------- > >>> 1 file changed, 43 insertions(+), 11 deletions(-) > >>> > >>> diff --git a/common/usb_storage.c b/common/usb_storage.c index > >>> 7e6e52d..7b5ad07 100644 > >>> --- a/common/usb_storage.c > >>> +++ b/common/usb_storage.c > >>> @@ -101,16 +101,15 @@ struct us_data { }; > >>> > >>> #ifdef CONFIG_USB_EHCI > >>> -/* > >>> - * The U-Boot EHCI driver can handle any transfer length as long as > >>> there is > >>> - * enough free heap space left, but the SCSI READ(10) and WRITE(10) > >>> commands are > >>> - * limited to 65535 blocks. > >>> - */ > >>> -#define USB_MAX_XFER_BLK 65535 > >>> +#define USB_XFER_BLK_TBL_SZ 5 > >>> +static unsigned short usb_xfer_blk_tbl[5] = {4096, 8192, 16384, > >>> +32768, 65535}; > >> > >> You should stick to using one block less than the power of two, the > >> controllers react to that a bit better. > > > > Hello Marek, > > > > I agree to above point, Will change the logic to use one block less > > than power of two i.e. 4095, 8191... 65535 > > > >> Each value in this table can then be calculated really trivially, it's: > >> > >> (1 << (12 + n)) - 1 > >> > > > > Prior to current implementation, I created USB_MIN_XFER_BLK=4096 and > > USB_MAX_XFER_BLK=65535 macros. And started the logic to multiple and > > divide by two to reach USB_MAX_XFER_BLK. Then thought, calculation > > would be costlier than indexing an array. Hello Marek, > > Since the numbers are 16bit tops, they will most likely end up being optimized to mov > rN, #imm16 or mov rN, imm16 + sub rN, #1 . That's two local instructions tops, > which will always be at least as fast as any memory fetch. > Ok, I agree to your point. Will change the logic to use above formula as mentioned by you in v2. > > Please comment. > > > >> You also don't need such static data. > >> > > > > Let me share the background for keeping this variable, It is taken to > > store the last optimal value for next read/write operation. And these > > value is reset to minimum when another USB device is connected. > > Consider the scenario where you have two sticks plugged in and mix reading from > both. Your approach with static variable will fail miserably. > You are right, I missed it completely. Above logic would have been possible if at time of changing the current device "usb dev ..", I reset the value to minimum again as we I have done when new device is connected. But "usb dev .." doesn?t seem to mapped to common/usb_storage.c code. Hence, it is difficult to retain value keeping a static variable. I will change the logic to start from minimum and try to go to maximum in every read/write in v2. Best Regards, Rajesh Bhagat > > Refer below log: > > > > 1st time (Iterated over all the possible size) => mw 81000000 55555555 > > 4000000; mw a0000000 aaaaaaaa 4000000; usb write a0000000 0 80000; usb > > read 81000000 0 80000; cmp.b a0000000 81000000 10000000; > > > > USB write: device 0 block # 0, count 524288 ... usb_read: retry #2, > > xfer_blk 4096, smallblks 4096 > > usb_read: retry #2, xfer_blk 8192, smallblks 8192 > > usb_read: retry #2, xfer_blk 16384, smallblks 16384 > > usb_read: retry #2, xfer_blk 32768, smallblks 32768 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 4103 > > 524288 blocks write: OK > > > > 2nd time (It started form 65535 blocks as it is last optimal value) => > > mw 81000000 55555555 4000000; mw a0000000 aaaaaaaa 4000000; usb write > > a0000000 0 80000; usb read 81000000 0 80000; cmp.b a0000000 81000000 > > 10000000; > > > > USB write: device 0 block # 0, count 524288 ... usb_read: retry #2, > > xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 65535 > > usb_read: retry #2, xfer_blk 65535, smallblks 8 > > 524288 blocks write: OK > > > > And I observed this value is different for read/write, Hence second > > patch is sent for handle that situation. > > > > Best Regards, > > Rajesh Bhagat > > > >>> #else > >>> -#define USB_MAX_XFER_BLK 20 > >>> +#define USB_XFER_BLK_TBL_SZ 1 > >>> +static unsigned short usb_xfer_blk_tbl[1] = {20}; > >>> #endif > >>> > >>> +static unsigned short USB_MAX_XFER_BLK; > >> > >> This value is different on per-device basis, how can it be static data ? > >> > >>> #ifndef CONFIG_BLK > >>> static struct us_data usb_stor[USB_MAX_STOR_DEV]; #endif @@ > >>> -1117,7 > >>> +1116,8 @@ static unsigned long usb_stor_read(struct blk_desc > >>> +*block_dev, > >> lbaint_t blknr, > >>> unsigned short smallblks; > >>> struct usb_device *udev; > >>> struct us_data *ss; > >>> - int retry; > >>> + int retry, next = LOG2((USB_MAX_XFER_BLK + 1) / > usb_xfer_blk_tbl[0]); > >>> + bool retry_flag = false; > >>> ccb *srb = &usb_ccb; > >>> #ifdef CONFIG_BLK > >>> struct blk_desc *block_dev; > >>> @@ -1158,6 +1158,8 @@ static unsigned long usb_stor_read(struct > >>> blk_desc > >> *block_dev, lbaint_t blknr, > >>> else > >>> smallblks = (unsigned short) blks; > >>> retry_it: > >>> + debug("usb_read: retry #%d, xfer_blk %hu, smallblks %hu\n", > >>> + retry, USB_MAX_XFER_BLK, smallblks); > >>> if (smallblks == USB_MAX_XFER_BLK) > >>> usb_show_progress(); > >>> srb->datalen = block_dev->blksz * smallblks; @@ -1165,14 +1167,26 > >>> @@ retry_it: > >>> if (usb_read_10(srb, ss, start, smallblks)) { > >>> debug("Read ERROR\n"); > >>> usb_request_sense(srb, ss); > >>> - if (retry--) > >>> + if (retry--) { > >>> + /* decrease the USB_MAX_XFER_BLK */ > >>> + if (next > 0) { > >>> + smallblks = usb_xfer_blk_tbl[--next]; > >>> + USB_MAX_XFER_BLK = smallblks; > >>> + } > >>> + retry_flag = true; > >>> goto retry_it; > >>> + } > >>> blkcnt -= blks; > >>> break; > >>> } > >>> start += smallblks; > >>> blks -= smallblks; > >>> buf_addr += srb->datalen; > >>> + > >>> + /* try to increase the USB_MAX_XFER_BLK */ > >>> + if (next < USB_XFER_BLK_TBL_SZ - 1) > >>> + if (!retry_flag && usb_xfer_blk_tbl[next + 1] <= blks) > >>> + USB_MAX_XFER_BLK = usb_xfer_blk_tbl[++next]; > >>> } while (blks != 0); > >>> ss->flags &= ~USB_READY; > >>> > >>> @@ -1199,7 +1213,8 @@ static unsigned long usb_stor_write(struct > >>> blk_desc > >> *block_dev, lbaint_t blknr, > >>> unsigned short smallblks; > >>> struct usb_device *udev; > >>> struct us_data *ss; > >>> - int retry; > >>> + int retry, next = LOG2((USB_MAX_XFER_BLK + 1) / > usb_xfer_blk_tbl[0]); > >>> + bool retry_flag = false; > >>> ccb *srb = &usb_ccb; > >>> #ifdef CONFIG_BLK > >>> struct blk_desc *block_dev; > >>> @@ -1244,6 +1259,8 @@ static unsigned long usb_stor_write(struct > >>> blk_desc > >> *block_dev, lbaint_t blknr, > >>> else > >>> smallblks = (unsigned short) blks; > >>> retry_it: > >>> + debug("usb_write: retry #%d, xfer_blk %hu, smallblks %hu\n", > >>> + retry, USB_MAX_XFER_BLK, smallblks); > >>> if (smallblks == USB_MAX_XFER_BLK) > >>> usb_show_progress(); > >>> srb->datalen = block_dev->blksz * smallblks; @@ -1251,14 +1268,26 > >>> @@ retry_it: > >>> if (usb_write_10(srb, ss, start, smallblks)) { > >>> debug("Write ERROR\n"); > >>> usb_request_sense(srb, ss); > >>> - if (retry--) > >>> + if (retry--) { > >>> + /* decrease the USB_MAX_XFER_BLK */ > >>> + if (next > 0) { > >>> + smallblks = usb_xfer_blk_tbl[--next]; > >>> + USB_MAX_XFER_BLK = smallblks; > >>> + } > >>> + retry_flag = true; > >>> goto retry_it; > >>> + } > >>> blkcnt -= blks; > >>> break; > >>> } > >>> start += smallblks; > >>> blks -= smallblks; > >>> buf_addr += srb->datalen; > >>> + > >>> + /* try to increase the USB_MAX_XFER_BLK */ > >>> + if (next < USB_XFER_BLK_TBL_SZ - 1) > >>> + if (!retry_flag && usb_xfer_blk_tbl[next + 1] <= blks) > >>> + USB_MAX_XFER_BLK = usb_xfer_blk_tbl[++next]; > >>> } while (blks != 0); > >>> ss->flags &= ~USB_READY; > >>> > >>> @@ -1331,6 +1360,9 @@ int usb_storage_probe(struct usb_device *dev, > >>> unsigned > >> int ifnum, > >>> break; > >>> } > >>> > >>> + /* Initialize the current transfer blocks to minimum value */ > >>> + USB_MAX_XFER_BLK = usb_xfer_blk_tbl[0]; > >>> + > >>> /* > >>> * We are expecting a minimum of 2 endpoints - in and out (bulk). > >>> * An optional interrupt is OK (necessary for CBI protocol). > >>> > >> > >> > >> -- > >> Best regards, > >> Marek Vasut > > > -- > Best regards, > Marek Vasut