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Commit e8f8c14d authored by Paul Zimmerman's avatar Paul Zimmerman Committed by Greg Kroah-Hartman
Browse files

usb: dwc2: clip max_transfer_size to 65535 



Clip max_transfer_size to 65535 for host. dwc2_hc_setup_align_buf()
allocates coherent buffers with this size, and if it's too large we
can exhaust the coherent DMA pool.

Tested on Raspberry Pi and Altera SOCFPGA.

Signed-off-by: default avatarPaul Zimmerman <paulz@synopsys.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d00b4142

drivers/usb/dwc2/core.c

+7 −0
Original line number Diff line number Diff line
@@ -2743,6 +2743,13 @@ int dwc2_get_hwparams(struct dwc2_hsotg *hsotg) 
	width = (hwcfg3 & GHWCFG3_XFER_SIZE_CNTR_WIDTH_MASK) >>

		GHWCFG3_XFER_SIZE_CNTR_WIDTH_SHIFT;

	hw->max_transfer_size = (1 << (width + 11)) - 1;

	/*

	 * Clip max_transfer_size to 65535. dwc2_hc_setup_align_buf() allocates

	 * coherent buffers with this size, and if it's too large we can

	 * exhaust the coherent DMA pool.

	 */

	if (hw->max_transfer_size > 65535)

		hw->max_transfer_size = 65535;

	width = (hwcfg3 & GHWCFG3_PACKET_SIZE_CNTR_WIDTH_MASK) >>

		GHWCFG3_PACKET_SIZE_CNTR_WIDTH_SHIFT;

	hw->max_packet_count = (1 << (width + 4)) - 1;