@@ -28,6 +28,8 @@
* status of a command.
*/
+#include <linux/blkdev.h>
+#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/mutex.h>
@@ -99,6 +101,7 @@ static int slave_alloc (struct scsi_device *sdev)
static int slave_configure(struct scsi_device *sdev)
{
struct us_data *us = host_to_us(sdev->host);
+ struct device *dev = us->pusb_dev->bus->sysdev;
/*
* Many devices have trouble transferring more than 32KB at a time,
@@ -129,6 +132,14 @@ static int slave_configure(struct scsi_device *sdev)
}
/*
+ * The max_hw_sectors should be up to maximum size of a mapping for
+ * the device. Otherwise, a DMA API might fail on swiotlb environment.
+ */
+ blk_queue_max_hw_sectors(sdev->request_queue,
+ min_t(size_t, queue_max_hw_sectors(sdev->request_queue),
+ dma_max_mapping_size(dev) >> SECTOR_SHIFT));
+
+ /*
* Some USB host controllers can't do DMA; they have to use PIO.
* They indicate this by setting their dma_mask to NULL. For
* such controllers we need to make sure the block layer sets
This patch fixes an issue that the following error happens on swiotlb environment: xhci-hcd ee000000.usb: swiotlb buffer is full (sz: 524288 bytes), total 32768 (slots), used 1338 (slots) On the kernel v5.1, block settings of a usb-storage with SuperSpeed were the following so that the block layer will allocate buffers up to 64 KiB, and then the issue didn't happen. max_segment_size = 65536 max_hw_sectors_kb = 1024 After the commit 09324d32d2a0 ("block: force an unlimited segment size on queues with a virt boundary") is applied, the block settings are the following. So, the block layer will allocate buffers up to 1024 KiB, and then the issue happens: max_segment_size = 4294967295 max_hw_sectors_kb = 1024 To fix the issue, the usb-storage driver checks the maximum size of a mapping for the device and then adjusts the max_hw_sectors_kb if required. After this patch is applied, the block settings will be the following, and then the issue doesn't happen. max_segment_size = 4294967295 max_hw_sectors_kb = 256 Fixes: 09324d32d2a0 ("block: force an unlimited segment size on queues with a virt boundary") Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> --- This patch can be applied on v5.3-rc1. Changes from v2: - Add Alan's Acked-by. https://patchwork.kernel.org/patch/10992539/ Changes from v1: - Call blk_queue_max_hw_sectors() for the maximum size of mapping unconditionally to simplify the code by using read the value back from the queue in the end. - Add a comment on the code. - On v1, I got Reviewed-by from Christoph. But, I changed the code a little, I removed the Reviewed-by. https://patchwork.kernel.org/patch/10992985/ drivers/usb/storage/scsiglue.c | 11 +++++++++++ 1 file changed, 11 insertions(+)