This version folds in Alan's example. ++doug --- >From f644b337771374178d5585bcedf8153f5b45f2d6 Mon Sep 17 00:00:00 2001 From: Doug Maxey <dwm@xxxxxxxxxxxxxx> Date: Tue, 27 Nov 2007 18:42:42 -0600 Subject: [PATCH 1/1] usb-storage: limit devices that cannot handle 32k transfers When a device cannot handle the smallest previously limited transfer size (64 blocks) without stalling, limit the device to the amount of packets that fit in a platform native page. The lowest possible limit is PAGE_CACHE_SIZE, so if the device is ever used on a platform that has larger than 8K pages, you lose unless you can convince the device firmware folks to fix the issue. Cc: Mathew Dharm <mdharm-scsi@xxxxxxxxxxxxxxxxxx> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Cc: Pete Zaitcev <zaitcev@xxxxxxxxxx> Signed-off-by: Doug Maxey <dwm@xxxxxxxxxxxxxx> --- drivers/usb/storage/scsiglue.c | 12 +++++++++--- drivers/usb/storage/unusual_devs.h | 7 +++++++ include/linux/usb_usual.h | 5 ++++- 3 files changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c index 1ba19ea..62e9e94 100644 --- a/drivers/usb/storage/scsiglue.c +++ b/drivers/usb/storage/scsiglue.c @@ -114,9 +114,15 @@ static int slave_configure(struct scsi_device *sdev) * while others have trouble with more than 64K. At this time we * are limiting both to 32K (64 sectores). */ - if ((us->flags & US_FL_MAX_SECTORS_64) && - sdev->request_queue->max_sectors > 64) - blk_queue_max_sectors(sdev->request_queue, 64); + if (us->flags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) { + unsigned int max_sectors = 64; + + if (us->flags & US_FL_MAX_SECTORS_MIN) + max_sectors = PAGE_CACHE_SIZE >> 9; + if (sdev->request_queue->max_sectors > max_sectors) + blk_queue_max_sectors(sdev->request_queue, + max_sectors); + } /* We can't put these settings in slave_alloc() because that gets * called before the device type is known. Consequently these diff --git a/drivers/usb/storage/unusual_devs.h b/drivers/usb/storage/unusual_devs.h index 22ab238..f464b18 100644 --- a/drivers/usb/storage/unusual_devs.h +++ b/drivers/usb/storage/unusual_devs.h @@ -376,6 +376,13 @@ UNUSUAL_DEV( 0x04b0, 0x0417, 0x0100, 0x0100, US_SC_DEVICE, US_PR_DEVICE, NULL, US_FL_FIX_CAPACITY), +/* Reported by Doug Maxey (dwm@xxxxxxxxxxxxxx) */ +UNUSUAL_DEV( 0x04b3, 0x4001, 0x0110, 0x0110, + "IBM", + "IBM RSA2", + US_SC_DEVICE, US_PR_CB, NULL, + US_FL_MAX_SECTORS_MIN), + /* BENQ DC5330 * Reported by Manuel Fombuena <mfombuena@xxxxxx> and * Frank Copeland <fjc@xxxxxxxxxxxxxxxxxxx> */ diff --git a/include/linux/usb_usual.h b/include/linux/usb_usual.h index 1b792b9..a417b09 100644 --- a/include/linux/usb_usual.h +++ b/include/linux/usb_usual.h @@ -48,7 +48,10 @@ US_FLAG(IGNORE_DEVICE, 0x00000800) \ /* Don't claim device */ \ US_FLAG(CAPACITY_HEURISTICS, 0x00001000) \ - /* sometimes sizes is too big */ + /* sometimes sizes is too big */ \ + US_FLAG(MAX_SECTORS_MIN,0x00002000) \ + /* Sets max_sectors to arch min */ + #define US_FLAG(name, value) US_FL_##name = value , enum { US_DO_ALL_FLAGS }; -- 1.5.3.6 ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ linux-usb-devel@xxxxxxxxxxxxxxxxxxxxx To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel