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authorDuncan Laurie <dlaurie@chromium.org>2013-09-12 13:27:15 -0700
committerIsaac Christensen <isaac.christensen@se-eng.com>2014-08-14 01:45:35 +0200
commit3a65d857ead2fcb8dd30a52cf4f68554a4bff275 (patch)
tree0b63bbea361cdb0cdcf64883f1f819b1b718356a /payloads
parent8f993784ef71f451995dd67fc709b88399c8a7e9 (diff)
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libpayload: usbmsc: Split transfers into 64KB chunks
Add a new function to split transfer requests into chunks of 64KB in order to be as compatible as possible with devices that choke when sent large transfer requests. Change-Id: Id11990bd149af14af5535de4af47bda21d1ab51e Signed-off-by: Duncan Laurie <dlaurie@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/169170 Reviewed-by: Julius Werner <jwerner@chromium.org> (cherry picked from commit 4c413b007aa23da830877127dd556c4c38b43042) Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com> Reviewed-on: http://review.coreboot.org/6636 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <patrick@georgi-clan.de> Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Diffstat (limited to 'payloads')
-rw-r--r--payloads/libpayload/drivers/usb/usbmsc.c48
1 files changed, 47 insertions, 1 deletions
diff --git a/payloads/libpayload/drivers/usb/usbmsc.c b/payloads/libpayload/drivers/usb/usbmsc.c
index 2d28fbd12..0259b8d36 100644
--- a/payloads/libpayload/drivers/usb/usbmsc.c
+++ b/payloads/libpayload/drivers/usb/usbmsc.c
@@ -125,6 +125,9 @@ usb_msc_destroy (usbdev_t *dev)
const int DEV_RESET = 0xff;
const int GET_MAX_LUN = 0xfe;
+/* Many USB3 devices do not work with large transfer requests.
+ * Limit the request size to 64KB chunks to ensure maximum compatibility. */
+const int MAX_CHUNK_BYTES = 1024 * 64;
const unsigned int cbw_signature = 0x43425355;
const unsigned int csw_signature = 0x53425355;
@@ -363,7 +366,7 @@ readwrite_blocks_512 (usbdev_t *dev, int start, int n,
* @return 0 on success, 1 on failure
*/
int
-readwrite_blocks (usbdev_t *dev, int start, int n, cbw_direction dir, u8 *buf)
+readwrite_chunk (usbdev_t *dev, int start, int n, cbw_direction dir, u8 *buf)
{
cmdblock_t cb;
memset (&cb, 0, sizeof (cb));
@@ -382,6 +385,49 @@ readwrite_blocks (usbdev_t *dev, int start, int n, cbw_direction dir, u8 *buf)
!= MSC_COMMAND_OK ? 1 : 0;
}
+/**
+ * Reads or writes a number of sequential blocks on a USB storage device
+ * that is split into MAX_CHUNK_BYTES size requests.
+ *
+ * As it uses the READ(10) SCSI-2 command, it's limited to storage devices
+ * of at most 2TB. It assumes sectors of 512 bytes.
+ *
+ * @param dev device to access
+ * @param start first sector to access
+ * @param n number of sectors to access
+ * @param dir direction of access: cbw_direction_data_in == read,
+ * cbw_direction_data_out == write
+ * @param buf buffer to read into or write from.
+ * Must be at least n*sectorsize bytes
+ * @return 0 on success, 1 on failure
+ */
+int
+readwrite_blocks (usbdev_t *dev, int start, int n, cbw_direction dir, u8 *buf)
+{
+ int chunk_size = MAX_CHUNK_BYTES / MSC_INST(dev)->blocksize;
+ int chunk;
+
+ /* Read as many full chunks as needed. */
+ for (chunk = 0; chunk < (n / chunk_size); chunk++) {
+ if (readwrite_chunk (dev, start + (chunk * chunk_size),
+ chunk_size, dir,
+ buf + (chunk * MAX_CHUNK_BYTES))
+ != MSC_COMMAND_OK)
+ return 1;
+ }
+
+ /* Read any remaining partial chunk at the end. */
+ if (n % chunk_size) {
+ if (readwrite_chunk (dev, start + (chunk * chunk_size),
+ n % chunk_size, dir,
+ buf + (chunk * MAX_CHUNK_BYTES))
+ != MSC_COMMAND_OK)
+ return 1;
+ }
+
+ return 0;
+}
+
/* Only request it, we don't interpret it.
On certain errors, that's necessary to get devices out of
a special state called "Contingent Allegiance Condition" */