UPSTREAM: usb: gadget: mass_storage: Fix cdrom data transfers on MAC-OS
During cdrom emulation, the response to read_toc command must contain
the cdrom address as the number of sectors (2048 byte sized blocks)
represented either as an absolute value (when MSF bit is '0') or in
terms of PMin/PSec/PFrame (when MSF bit is set to '1'). Incase of
cdrom, the fsg_lun_open call sets the sector size to 2048 bytes.
When MAC OS sends a read_toc request with MSF set to '1', the
store_cdrom_address assumes that the address being provided is the
LUN size represented in 512 byte sized blocks instead of 2048. It
tries to modify the address further to convert it to 2048 byte sized
blocks and store it in MSF format. This results in data transfer
failures as the cdrom address being provided in the read_toc response
is incorrect.
Fixes: 3f565a363c
("usb: gadget: storage: adapt logic block size to bound block devices")
Cc: stable@vger.kernel.org
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Link: https://lore.kernel.org/r/1661570110-19127-1-git-send-email-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 9d4dc16ec71bd6368548e9743223e449b4377fc7)
Bug: 245221519
Change-Id: I50687e4dfc2b26d35adce50e51b54d28fb85967e
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
This commit is contained in:

committed by
Treehugger Robot

parent
4135365b5d
commit
2d8afda40e
@@ -294,8 +294,10 @@ EXPORT_SYMBOL_GPL(fsg_lun_fsync_sub);
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void store_cdrom_address(u8 *dest, int msf, u32 addr)
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{
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if (msf) {
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/* Convert to Minutes-Seconds-Frames */
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addr >>= 2; /* Convert to 2048-byte frames */
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/*
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* Convert to Minutes-Seconds-Frames.
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* Sector size is already set to 2048 bytes.
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*/
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addr += 2*75; /* Lead-in occupies 2 seconds */
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dest[3] = addr % 75; /* Frames */
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addr /= 75;
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